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Compatibility [05] Front derailleurs

Updated: 01/04/2021.

This post explains bicycle front derailleur compatibility of various makes and models. For a detailed explanation of front derailleur (FD in the rest of this post) mounting systems, cable routing and capacity, read this article: Front derailleur.

Before you start, to avoid any misunderstanding:
please take the 5 minutes needed to read the compatibility articles use instructions.

FDs differ in several categories (they are all explained with pictures in the above linked Front derailleur article):

  1. Mounting: braze on, clamp mounted, or direct mounted
  2. Cable routing: top pull, bottom pull, or bidirectional pull (double pull)
  3. Big front chainring teeth number that FD is designed for and mounting angle
  4. Number of front chainrings: double vs triple
  5. FD cage rotation relative to the clamp position: high clamp, low clamp, or the new Shimano side-swing
  6. MTB vs Road FD
  7. Number of speeds (number of rear sprockets and chain width) FD is designed for
  8. Exceptions


1. Mounting

FDs are made for mounting on frame fixed braze on, or come with clamps for mounting on the seat tube. If FD comes with a clamp, seat tube diameter must match the clamp diameter. A newer standard, used on mountain bikes is the direct mount, it is explained at the end of this chapter.

If a frame comes with a brazed on FD mount, in order to mount a clamp on FD, the frame mount must be removed (cut off). In some (rare) cases the clamp can be put above/below the frame mount, so it can stay, as long as it doesn’t interfere with FD movement and proper mounting relative to the front chainrings.

Frame with a front derailleur braze on holder.
Frame with a front derailleur braze on holder.

Standard clamp (and seat tube) sizes are:
1 1/8″ (28.6 mm)
1 1/4″ (31.8 mm) and
1 3/8″ (34.9 mm)

If a FD is a braze on type and the frame doesn’t have a FD hanger (or the frame hanger is too low/high for the size of front chainrings used), a separate clamp can be bought so that FD can be fixed to it. This is a much more universal type of FD.

Front derailleur clamp. It is used when a braze on front derailleur needs to be mounted on a frame without derailleur holders.
Front derailleur clamp.
It is used when a braze on front derailleur needs to be mounted on a frame without derailleur holders.

Direct mount FDs can often be fitted to a frame without direct mount attachment holes using an adapter, enabling the FD to be secured by a (threaded) BB shell. There are also adapters for frames with a round seat tube cross section of a standard width, so that a direct mount FD can be attached to them.

Frames with exotic seat tubes (either by cross section that isn’t round, or by diameter that varies from the three standar sizes), often have FD mounts made on the frame. If, for any reason, those mounts can’t be used (damaged, or not fitting the FD at hand), an adapter can be used – held in place by the BB shell – for frames with a threaded BB at least.


2. Cable routing

There are FDs that have a cable attached from below, from above, or from any of the two. Frames usually have only one type of cable routing.

Double pull FD. Enables routing from either side. Here, two cables are routed, from the top and from the bottom. Of course, only one cable is mounted in real life - either from the top, or from the bottom. Never two! :)
Double pull FD.
Enables routing from either side. Here, two cables are routed, from the top and from the bottom. Of course, only one cable is mounted in real life – either from the top, or from the bottom. Never two! 🙂

With double routed FDs this isn’t important, but for the other models, if the FD’s cable routing doesn’t match the frame design, there is a special adapter that can reverse the cable direction.

FD cable routing adapter. Enables reversal of cable routing to the front derailleur.
FD cable routing adapter.
Enables reversal of cable routing to the front derailleur.

In the picture above, the frame has cable routing so that FD cable comes from above. FD is designed for bottom cable routing. The adapter with a wheel onto which the cable is placed is mounted on the seat tube below the FD, so that the cable can go over it and up to the FD. Everyone is happy. 🙂

Almost all the road FDs have bottom pull cable routing, while most MTB FDs have either top, or dual cable pull. 


3. Teeth number (the size) of the largest front chainring a)
and mounting angle b)

a) teeth number

FD is curved in order to align with the curve of the largest front chainring. A typical MTB chainring has 42 teeth, while road bike chainrings often come with 53 teeth. A smaller chainring requires the FD to have a much more curve in order to align (and vice versa).

Well placed FD that perfectly aligns with the chainring shape.
Well placed FD that perfectly aligns with the chainring curve.

Imagine in the picture above that the FD cage is shaped to match the middle chainring. It would have to be mounted either too high, or it’s rear part would bump into the big chainring, since it has too sharp a curve.

FDs are usually made to match chainrings with 42, 48, 50, or 53 teeth. If FD and large chainring are mismatched for a couple of teeth, there’s no problems, it’s close enough. If, however, a difference is large, the following problems occur:

  • Chainring has a lot more teeth than the FD is designed for: like explained above. FD will have to be mounted too high, which will make shifting slow, poor and might cause chain rub on the rear lowest part of the FD after shifting onto the smallest chainring.
  • Chainring has a lot less teeth than the FD is designed for: front part of FD will be correctly positioned, while the rear part of the cage will remain high up, and the chainring curves sharply down. It will not align. This will not hurt shifting, but will cause a lot of chain rub on the FD cage – as soon as some shifting gears in the rear sprockets causes minimal amount of cross chaining.

b) mounting angle

Seat tube angle (onto which FD is mounted) is usually about 70 to 73 degrees for road bikes, while MTBs usually have a bit steeper seat tubes (closer to vertical vertical compared to road bike ones), of around 75 or more degrees. If a FD designed for a more vertical tube is mounted on a tube that has a less vertical angle, the effect will be similar to that of combining a FD designed for a lot smaller chainring, with a chainring that is bigger. And vice versa.

Though this is a bit misleading. For a full disclosure: modern road and MTB frames don’t really differ all that much by seat tube angles. What differs is the angle between the chainstay and the seat tube. MTB bikes have that angle a lot smaller, compared to road bikes (by roughly 5, or more degrees), and that is the angle that matters as far as front derailleurs are concerned (see the next paragraph, below the picture).

A FD designed for a lot steeper tube is put on a more vertical one. The rear part of the cage is too high, even though FD is mounted at the correct height.
A FD designed for a less vertically angled tube is put on a more vertical one.
The rear part of the cage is too high, even though FD is mounted at the correct height.

It is worth noting (thanks to Drew for pointing it out) that frame manufacturers provide seat tube angle as measured from horizontal (which matters for riding position fitting), while Shimano (for one) notes their front derailleur angle as the one between the seat tube and the chainstay (which actually is what matters for the front derailleurs). So those (“Shimano”) angles are often 61 to 66° degrees for road FDs, and 66 to 69° for MTB front derailleurs.

Similar problems can occur if the mounting position isn’t correct – happens on some special, or custom built frames.

A frame on which, because of the low rear axle, FD must be placed a bit behind the seat tube. A specific case.
A frame on which, because of the low rear axle, FD must be placed a bit behind the seat tube.
A specific case.

If a FD is a braze on mounted type, this can be corrected with made adapters:

Adapter for changing FD angle to a steeper one and for moving it to the rear.
Adapter for changing FD angle to a steeper one and for moving it to the rear.


4. Double vs triple

FDs are made in two variants: for double and for triple front chainrings.

Double vs triple FD
Double vs triple FD

Double FD will work with a triple chainring if the difference in teeth number between the smallest and the largest chainring is rather small (which defeats the purpose of a triple chainring though). For example a 34-42-48 chainring. Also, if the operation (movement) of the FD is limited to the two largest chainrings, it can work OK.

Triple FD will work on a double chainring if the difference in teeth number between the chainrings isn’t bigger than 12. One can “get away” with 14 as well, but the lower difference, the better.

Compact cranksets, with two chainrings that vastly differ in size (usually 34-50 combination) will work well only with double FDs with the curve appropriate for the big ring size (50 to 52). Even when using a double FD, it is best to keep the tooth cound difference up to 16 (like with 34-50, or 36-52 chainring combinations).


5. High clamp, low clamp, or side-swing

With older standard for FDs, the cage is below the mount, so that FD cage swings below the FD body. These are the high clamp FDs. Low clamp is a newer Shimano system meant for MTBs with rear suspension. FD cage is practically in line with the mount. This leaves more room for mounting the rear suspension to the seat tube. Previously used terms for this were bottom swing (for high clamp) and top swing (for low clamp), but with the introduction of Shimano side-swing system (explained at the end of this chapter), these terms are no longer precise enough.

If the bike has no rear suspension, or there is enough room for a standard FD below the suspension, it is irrelevant which type of FD is mounted (as long as it’s suitable in terms of other explained criteria – angle, size etc.).

The newest Shimano system is the side-swing, where the cage rotates sideways. These FDs can be clamped with a high clamp, low clamp, or using a direct mount system.

Shimano Side-Swing front derailleur
Shimano Side-Swing front derailleur


6. MTB vs road FD

Shimano road and MTB FDs have different cable pull ratio – that is the amount of FD movement for each mm of cable movement. This means that MTB FDs might not work well with indexed road shifters and vice versa.

With double chainrings, this issue can be fixed with adjusting limit screws and it could be made to work. With triple chainrings, it is harder to get it to work properly. However, FD cage is a lot wider than the chain and triple FDs have just 3 positions, so depending on particular shifter – FD combination, even that can sometimes be made to work OK.

Having said all this and in spite of officially different cable pull, all the FDs almost always work OK with all the shifters, regardless whether it is road, or MTB. Exception are the Shimano 11 speed road FDs and Shimano Tiagra 4700 10 speed FDs – they have a (vastly) different cable pull (and cable anchor arm), so they are not compatible. So, while this will not shift perfectly, especially with triples, it is worth giving a try and seeing if it’s good enough for one’s criteria – if what one has on hand are mismatched road and mtb shifters and FDs. If it doesn’t work satisfactory, the cheaper option is to find a FD that matches the shifter.


7. Number of speeds

The last AND the least important.  🙂

FDs are made for a certain number of speeds, i.e. number of rear sprockets. The more speeds, the narrower the chain. There are FDs for 6 to 8 speeds, then for 9, 10 and 11 speeds. Cage width is made to match the planned chain width.

FDs for 9 (left) and 10 speeds (right)
FDs for 9 (left)
and 10 speeds (right)

However, since the chain moves left-right on the rear sprockets, FD cage is a lot wider than the chain. That is why it is possible to mount a 10 speed FD and use it with a 6 to 8 speed chain.

FDs are very forgiving in terms of speed number (even in terms of manufacturers), so they can be mixed and matched. One of the few pieces of equipment where it is possible to change a Campagnolo 10 speed with a Shimano 8 speed and it all works.

When a FD for more speeds is put on a chain for fewer speeds, the only bad effect is more chain rub. Since the FD cage is narrower, smaller angling of the chain (when changing gears at the back) will cause it to rub the FD cage. With indexed shifters, a trimming option can help, while with friction shifters this is not an issue.


8. Exceptions

Exception to this rule are Shimano 11 speed road FDs. They will not work very well with anything but Shimano 11 speed road shifters and Shimano Tiagra 4700 10 speed road shifters. Same goes for Tiagra 4700 FDs. Newest Campagnolo 11 speed system: Revolution 11+ (older one is Revolution 11) also requires matching (Revolution 11+) shifters and derailleurs. The reason for incompatibility lies in different cable attachment and amount of needed cable pull per gear change. Why was something that had already worked “fixed” has probably more to do with the marketing, than with the engineering department of the company.

Another exception is the new “gravel” group (with hydraulic brakes): Shimano GRX. Caple pull wise it’s the same as Tiagra 4700.

Related post – Front derailleur:

Bicycle front derailleur (FD). Types of front derailleurs, frame mount standards, FD compatibility...
Bicycle front derailleur (FD). Types of front derailleurs, frame mount standards, FD compatibility…


Compatibility posts are also available in eBook (printable and Kindle) and paperback editions on Amazon:

Bicycle drivetrain compatibility book
Bicycle drivetrain compatibility book
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85 thoughts on “Compatibility [05] Front derailleurs”

  1. Excellent information – thank you. Have been hunting the internet for answers on FD angle of inclination / curve to match front chain ring – and at last found the answer I needed .

    Reply
  2. Thanks!! Do you think a Shimano Sora R3000 FD will work with 36/22 or 38/24 chanrings? The FD limit is 46T

    Reply
    • It won’t work brilliantly, since the larger chainring is a lot smaller than what the FD is designed for.
      The fact that smaller chainring is also smaller than anything one would generally expect on a road double (34 is general, while 30 is the absolute minimal) certainly doesn’t help.

      Having said that, depending on one’s criteria of “good” (or “good enough”), it can be OK. Especially if (front) shifting under load is avoided (though that’s generally always advisory, but in this case even more so).

  3. Hi, I have Shimano Tiagra 4700 2×10 shifters and I need to use a top pull FD, but for road doesn’t exist…I see the Salsa fargo is using tiagra shifters and deore fd-m6025…is it correct?

    Reply
    • As far as I know, it’s not a perfect match, but for 2x drivetrains, it should work (4700 shifter will, as far as I know, pull more cable than needed per shift, but FD limit screws will keep it from oveshifting).

  4. Then If I will use any 2x shimano FD with tiagra 4700 road, playing with the screws It will work..not perfectly but works..isn’t?
    Even if the FD is a dyn-sis technology?

    Reply
    • It depends on your criteria. In my experience, for 2x, almost anything can be made to work OK. Not perfectly, as good as it possibly can – in terms of fast shifting, especially if attempted under (slight) load, but OK.

      However, I haven’t tried every possible combo, so can’t bet my life on it, sorry.

      Either way, do let us know what combo you end up making and how well it works.

  5. Hi, Hope you can help. I have bought a Calibre Stitch hybrid bike which i like, apart from the chain rubbing the front derailleur Claris) in a few gears when the chain is over angled. I have a spare front Altus, which has a wider gate. Do you think this would be compatible, and solve the rubbing problem?
    Thanks
    Chris

    Reply
    • If all is properly adjusted, having the chain rub when “severely cross chained” (as in – using the largest 2-3 rear sprockets from the largest front chainring and/or using the smallest 2-3 rear sprockets from the smallest front chainring) is a nice, harmless warning that your choice of gearing is not very good for the chain.

      I suppose that going with a wider cage FD can help eliminate that, or at least make it audible only for the very extreme combos (like the last 1 rear sprocket at the opposite side from the used front chainring, not 2-3 sprockets).

      Altus is not a perfect match for the Claris shifters, but it could be made to work satisfactory (depending on one’s criteria), especially with double front chainrings (with 3x it’s a bit more of a hassle). But it would be solving a problem that doesn’t really exist. Like using poor brakes, because a bicycle goes hardly when brakes are applied (sorry, can’t think of a better example).

  6. Thanks for that. I think i will just live with it, and take note when its rubbing, and change to a more appropriate gear.
    Regards
    Chris

    Reply
  7. Hi, Maybe you can help me out.
    It seems there is too little information around yet about 12 speed stuff. However, I’m trying to hack together a 2X12 system for a 29+ Drop bar frame for extended off-road touring (probably using 2.5”- 3.0”). I’m a Campagnolo user and have worked out everything except for the front derailleur / chainring combinations. I’m thinking I’d like somewhere from 19-120 gear inches. Jtek make a shift mate for Campy 12 – Shimano MTN 12. So with the Shimano 12s 10-45 rear cassette I’d need a 42-28 or 40-30 chainring or thereabouts (boost spaced 104-64 spider on Race Face cranks). This leaves me with a quandary. How do I get a derailleur to work with a 12 speed Campagnolo shifter over teeth that are that size? The smallest chainrings that Campagnolo suggests for the Chorus front derailleur are 48-32. Could this derailleur be modified to work? (Angled shims, Band on adapter for boost spacing). Would the Shimano 2X12 derailleur work better even though it’s specced for 36-26 chainrings. Is the pull of the Campagnolo 12 shifter going to be able to move the derailleur into the right position? I’m so lost.

    Thanks for the write up btw. I learnt more about the front derailleur from this post than all the previous things I’ve ever read.

    Reply
    • Hello,

      I’m afraid that I can hardly say anything you don’t already know – sorry. But won’t waste too much of your time (the reply is still under 10 pages long 🙂 ).

      Firstly I have to make a disclaimer: I live and work in Serbia, a rather poor, devastated country, so don’t see much of the new stuff – until it becomes the old stuff. 🙂
      My estimates from charts, specifications and manufacturer inquiries are usually correct, but think it’s fair to point out for stuff that I haven’t personally tested.
      To make things even worse, Campagnolo is like a unicorn here: everyone knows it’s nice and cool, but no one’s actually seen it! 🙂
      OK, being a mechanic, I get to see a few – more than the “normal” cyslists (if there is such a thing 🙂 ), but still not very much.

      Secondly, I’d give myself the liberty to add, even if not asked, that for touring I’d go with simpler, more robust stuff – like friction shifters and fewer cogs at the back.
      Using triple front chainrings.
      This easily provides wide enough gearing ratio, with gears still being “tight” enough so that the desired gear ratio is always available.
      Another advantage of such systems is they work flawlessly with practically any chain (or cassette for that matter) that you throw at them (this can matter in case of a malfunction while away from any well equipped store).

      OK, with all that out of the way:
      I would expect 42-30 to work OK with a derailleur for 48-32. If fast shifting under load is not needed (like when racing), and if one’s criteria of fast/smooth front shifting is not too strict, it would probably work OK. I’ve mix-matched road 50/53 large chainring double FDs with MTB cranks and had them do just fine – especially with the doubles.

      For mixing Shimano FD with Campagnolo shifter – I haven’t tried that, so will have to look up the manufacturer specs (if there are any cable pull specs) and see. I would bet a beer that it can be made to work, with a double, but can’t say for certain, unfortunately.

  8. Hi,
    Thanks for great content on the site! I have a bit of conundrum with my front mech setup, hoping you would be able to help maybe?
    I’m looking to build a CX bike around an old frame which is equipped for a top pull cable routing. I find it extremely hard to find a fitting FD
    – CX70 (top pull) seems to be good candidate, but it proves extremely hard to get (at least based on my attempts so far – either out of stock, or even when sellers claim they have this, in the end they delay and decline the order…) and then also I’m worried about compatibility – would it work with Tiagra 4700 shifter? (Shimano claims compatibility with 10 speed groupsets, but apparently 4700 has different pull ratio than previous ones…)
    – secondly, Ultegra FD-8000 claims to be “Dual Pull” which would mean both bottom and top; 105 and GRX seem to share the construction and also claim “more cable routing options” but any setup instructions only show the bottom pull setup – so how is that in real life?
    – finally another option would be to engage some MTB derailleur which more commonly come in top pull, but then again would that work OK with road shifters (Tiagra 4700 or 105 7000 series)?

    Thanks in advance for any insights on this!

    Cheers,
    Tomasz

    Reply
    • Shimano’s compatibility charts are given on their website and are usually quite conservative – meaning that whatever they say will work, works.

      4700 front shifter (as well as their 11 speed road shifters) pulls more cable than the other Shimano’s front shifters. For doubles, FD limit screws can help so one can make it work OK (depending on one’s criteria of how good it has to be for it to be considered “OK”).

      Stated “more cable options” means that the FD accepts both the “naked” cable, and the cable that comes with housing, all the way to the FD (the FD has a housing stop built in). However, for all I know, in order for that FD-8000 to accept top routed cables, one would need to use an adapter.

      Hope this helps, let me know if you have more questions.

      Relja

  9. Good day,

    Just wanted to know if the old 105 fd(5800) is compatible with the new 105 crankset (r7000)?

    Thank you in advance!!

    Reply
  10. Hi I just broke my cx70 on my CX bike so need a new top pull front deraulier with 31.8mm clamp but as metioned above a new cx70 is hard to obtain now.

    I have 105 STI 5700 shifters

    A run an altus mtb rear mech and it works perfect, this made me think try a mtb front mech also.

    48t big ring 34t small ring double 110bcd road crank.

    Read else where online that a XTR mtb front one may work for cx but there a a multitude of models, any advice what models of FD to try?

    How about:

    https://bike.shimano.com/en-US/product/component/deorext-m780/FD-M786.html

    Thankyou.

    Reply
    • I live in a country that is war/crisis torn and impoverished. So getting proper parts is often difficult – both because they aren’t available, as well as because of the price. Hence – I would try with whatever is at hand (old spare parts, trashed donor bikes etc.). FD-s aren’t too picky, especially if handled properly, with friction shifters. 🙂
      The point of this is that what I would do (and perhaps recommend) might not be the optimal choice for everyone. Now to the question at hand – what are the options?

      If in a position to order a new part, I would use what’s the most optimal choice.
      FD you linked is for 66 to 69 degrees chainstay angle (which is the angle between the seat tube and the chainstay).
      While most road FD-s are for 61 to 66 degrees chainstay angle.

      So that would be a deciding factor for me. To choose one that fits the bike best.

      As for compatibility – most Shimano road double FD-s are designed for 52 to 46 largest chainring, and can handle 34 toothed small chainring. The up-to 10 speed ones (apart from Tiagra 4700 FD-s) should work perfectly fine. There is no reason to go with an MTB FD if you already have road shifters – unless it matches your frame better.

      If the angle is over 66 degrees – the FD you linked should be OK.
      If the angle is 66 degrees, or smaller, I’d go with 10 speed 105 FD (5700 series, or older), or, if on a tighter budget, Sora 9 speed one:
      https://bike.shimano.com/en-US/product/component/sora-r3000/FD-R3000-B.html

  11. Hi Relja, When I looked on the map, I realized I was most likely passing by your shop during my many visits of my friends in NS. Well, next time I will stop by 🙂

    I would like to ask you few questions:

    I am riding 3×9 XT set on my 2009 GIANT Reign X0 (my old reliable friend). Now, the time to change both FD and RD came again, but this time I can not find 3×9 XT in the stores here (Slovakia) anymore. BTW: My Crankset is 42-32-22.
    FRONT DERAILLEUR
    The only options I found here for FD is 3×11:
    XT FD-M8000 pre 3×11 Side-swing. I can lead the cabe to the FD from the front, so that is fine and according to what you said 3×11 should be fine for 3×9 too. The only problem seems to be the 2 mm narrower cage. I kind of hope to find a way to make it +2mm wider…. ?

    More importantly:
    REAR DERAILLEUR
    I would like to get a cassette with 40T (or max 42T). https://tinyurl.com/y6hnto85
    But the only 9sp RD I foud still available is XT M772GS. I was trying to find the SGS model, but no succes. According to the official document the 772 RD can handle max 34T. Is there any solution to this?

    I was also considering to change to 10sp instead, but than I realized, that I will probably face the same problem as with 9sp – According to the official document the 10sp RD can handle max 34T. So I thought to use 11sp RD with 10sp shifter – but from your other article I realized it wont work either.
    Full 11sp, seems to me to much and to expensive…. and I would like to keep the 3-crank in the front.

    Is there a way to make the cage of the new FDs little wider? Would it be better to keep looking for original 3×9 FD?
    What do you think about the 9×3 or 10×3 with 40T option?
    Would you please have any other suggestion?
    THANK YOU.

    Reply
    • Hi,

      There’s my phone number on website contact info, so even if I’m not at the shop, feel free to contact me (Viber, WhatsApp, call, SMS…) when you’re in the neighbourhood. 🙂

      – Front derailleur –
      I would rather choose a lower end model (or, to be more precise, a “less top-end model”), like Deore, or Alivio, instead of buying an “11-speed” XT.
      Narrower cage will cause the chain to rub a bit sooner, when cross-chaining. So, for example, when on the big up front, now you might get away with no chain rub except when on the largest sprocket at the back. But with a narrower FD cage, you can expect to get some rubbing even when on the 2nd largest sprocket, or even the 3rd. Such cross chaining (big up front – 3rd largest at the rear) is not considered as “severe cross-chaining” by today’s standards, even though it’s not a perfect/very good combo.
      However, apart from that, I wouldn’t expect any more serious problems with the narrower chain. Though I’d still go with cheaper, quite good and durable Deore FD, preferably for 9, or 10 speeds.

      – Rear derailleur –

      Short answer:
      WolfTooth, or similar product sold by a less known (Chinese) brand can help. You can see it here:
      Video showing it installed on an 11-speed bicycle
      Video description has a link to on-line store, showing what the product looks like (though I would encourage shopping and supporting local bicycle stores).

      Longer answer:
      Shimano is often quite conservative when noting derailleur limits. So, for example, Shimano Alivio RD-M3100-SGS has the limit of 36 teeth (with a total chain-wrap capacity of 45 teeth).
      Depending on your frame’s current RD hanger design, if you screw in the B screw (almost) all the way in, you might see it nicely going over the 40 T chainring. 42 would be pushing it a bit too much, requiring the RD hanger extension (noted in the “Short answer”).

      There’s also a “trick” of screwing the B-screw the other way round, so its head is facing the RD hanger, making it push the RD even further, but I think that’s a bit more likely to bend the screw, or damage the small “lip” on the RD hanger that the screw hits into, pushing the derailleur. Similar goes for replacing the B-screw for a longer one (I think it’s an M3, or an M4 screw, would have to measure and check to be sure).

      “Philosophy” answer:
      I fail to see the point of having more than 34 teeth at the back, with a 22 T smallest front chainring. Even for muddy riding conditions, or loaded touring.
      So would advise giving a 34 teeth a try, if you haven’t already and found it not low enough gearing.

      As far as 3×10 goes, I prefer 3×7 with friction shifters: it’s super cheap, super durable, can use practically any modern multi-speed chain (tried from 6 to 10 speed chains on such setup so far, all worked fine). Good 2nd hand Shimano friction shifters, the ones made of steel/aluminium are practically indestructible, and very reliable. 7 and 8 speed chains are much cheaper. Same goes for 7-speed cassettes – cheaper, and there are 11-34 and 12-34 options available. And, with some spacers improvised from any old cassette, they fit 8-9-10-11 speed Shimano MTB freehubs (and road freehubs as well). Video explanation of 7-speed cassette on an 8-9-10-11 speed freehub.

      Relja

    • THANK YOU, Relja. I am clear now: I would keep all the components in my set as they should be – 3×9. The only think now is the cassette – i will grab either Deore CS-HG400 11-36T or Sunrace CS-M980 11-40T. I also found the clamp to make the RD bit longer: https://tinyurl.com/y3lpbzgz just in case the simple RD tunning would not help…

      I am using the 11-34T XT cassette, I remember when I installed my first 34T cassette I could noticed the difference from previous 11-32Ts – most of my trips are in the forest with quite steep hills. I do not know of anyone using 40T cassette on 22T crank, so I do not know how this would work, neither I know if the 36T would bring the desired effect. So both will be a kind of blind shots…

      AND, thank you for you invitation. 😉

  12. Hi Relja,

    Greetings from Spain. Thank you so much for all this technical info.

    Today I ‘succeeded’ mixing a Shimano GRX 400 10 speed FD with a Claris 3 speed shifter, 2 speed crankset and 9 speed chain.

    This GRX FD has features and adjustment bolts I never saw before at any front derailleur. It was little bit complex to assembly and adjust.

    I shortly tested on the turbo trainer. Let’s see how it works outdoors.

    Again, thank you for all this info.

    BR

    Diego

    Reply
  13. Pozdrav Relja,

    I am totally lost and helpless…. For more than a week I am trying to figure out what is happening.
    1 new out of box RD XT M772 – 9sp
    2 new out of box Cassete SunRace – 9sp (Tested also with previously used XT 9sp cassete with the same results)
    3 new chain HG93
    4 new out of box bowden and cable
    5 new out of box DEORE 9sp shifter (Tested also with previously used XT 9sp shifter with the same results)
    Sum Total: not able to make it work flawlessly. It is jumping over one of the cogs, the shiftig is not exact.

    3 prophesionals + me, where trying to make it work, they (we) didnt succed.
    Of course hanger was checked right from the begining.

    Absolutly frustrating. Would yu have any idea, what is going on here. Perhaps a bunch Gremlins are involved here, what do you thing? 🙂

    Reply
    • Pozdrav 🙂

      This video in Serbian shows and explains most of the possible problems (and troubleshooting) when tuning derailleurs:
      Štelovanje menjača bicikla

      When things like this happen, especially if I can’t even see the bike, I recommend starting “from the top”, testing even the “silly things” that “of course are correct” – sometimes mistakes happen even to the most experienced. So:

      1. Check the cables and housing – are they routed properly, are the housings for shifters (not for brakes).
      2. Is the cablee attached where it should be at the derailleur? Is it attached after the shifter has been shifted all the way to release the cable for as much as it can?
      3. Is the cassette tightened properly, without wiggling on the freehub?
      4. Is everything else tightened properly (RD, RD hanger, even shifters, wheel itself, in the dropouts)?
      5. RD B-screw position – is the top RD pulley wheel close enough to the cassette?
      6. Are the H(igh) and L(low) RD limit screws set properly – can the RD move all the way?
      7. Does it cause problems even when the chain is not crossed?
      8. Chain lenght of the new chain – is it optimal?

      Additional things to think about:
      When do the problems occur – only when pedaling with force, when riding in whichever way, or on the stand as well (with no rider on the bike)?
      Is there only one particular sprocket that gets skipped/problematic, or does it happen on several different sprockets? Are those several ones also always the same few, or does the problem happen all over the cassette?

      Relja

  14. Thanks!! Do you think a Shimano Sora R3000 shifter will work with 36/52 chanrings? The FD is deore

    Reply
    • I would expect it to work fine.
      Would be more worried about the Deore FD with a 52 largest chainring – expecting it to have to be set a bit higher than it is optimal, to prevent FD cage from hitting the chainring, since it has a sharper curve, since the cage is shaped for smaller front chainrings than 52 (so it has a smaller curve radius).

  15. I’m trying to replace an old XT Triple (22-32-42) 9 speed front mech. Will a Shimano 10 speed work ok? If not MTB specific, what about a Tiagra Triple? I currently run a Triple (26-36-46) 9 speed on a road bike with STI, but would the same front mech work with MTB LX 9 speed STI?

    Reply
    • FD should match the cranks (chainring size) – as explained in chapter 4 of this article.
      And it should match the shifter’s cable pull (see chapter 8).

      I’m not sure what kind of shifter and cranks are used on the bike we are talking about. Or planned to be used with the new FD.
      If it’s 26-36-46, with 9 speed Shimano road STIs, then I’d expect any triple FD for 6 to 9 speeds, that is designed for largest chainring of 44 to even 50 teeth to work acceptably well. This covers most road and MTB FDs.
      10 and 11 speed road FDs won’t work very well.

  16. Thanks for the blog, super useful for a beginner delving into bike upgrades

    I’ve got an old Giant CRX4 flat bar touring bike, with original 3x 8sp shimano components (Tourney 48-38-28) with a clamp fitted top pull front derailleur (bulky old version circa 2000s).

    The FD is so large I can easily clear 40mm tyres at front, yet only 30mm at rear. I’d like to run larger tyres for offroad/touring, so want a work around solution for the bulky FD.

    Side swing FD looks ideal, but Shimano have only put out 3x 10 speed for the Deore groupset as far as I can tell, and don’t yet, and probably wont do either a 3x 9 or 3x 8 speed side swing FD https://bike.shimano.com/en-EU/technologies/component/details/side-swing-front-derailleur.html

    Will I get away with running a Deore or SLX 3×10 side swing FD on a 3×8 setup? especially given the Deore is optimised for 42T max, and I’m running 48T?

    Are there other lower profile (non side swing) FD options that would buy me another 1cm of tire clearance?

    Reply
    • FD designed for 42 T will sit a bit higher with 48 T cranks (in order to avoid hitting the largest chainring with the rear part of the cage).
      That will create even more tyre clearance (in general/most cases), but will not make for perfect shifting.
      Especially when shifting up to the largest chainring.

      Now, that might work “OK”, well enough for your taste and needs – or it might not.

      Other options would be:
      – Sourcing a 48 T side swing FD.
      – Swapping the cranks for a 42 T model (though, with a smaller chainring, FD will sit lower, and probably provide less tyre clearance).
      – Perhaps, I’m not certain, a high-clamp (i.e. bottom-swing) FD might just offer a bit more tyre clearance, compared to a top swing one (if that is what’s currently on the bike).

      The potential problem here, from what I can conclude, is not the 3×10 vs 3×8, but the FD cage profile (if it’s not matched with the cranks).

      Finally, a “Solomon’s solution” as they say here, 37 mm is a whole lot wider than 30 mm. While it won’t be a mud/snow riding champion, it can be a capable off road and touring tyre. If one whole cm can’t be achieved, but it is manageable to get at least half, or so.

      P.S. Problem I have on my “haul-everything” bicycle (if that’s of use in this case, to consider) is that 42 T cranks, with a FD for 48 T, require the FD to sit so low that its cage hits against the chainstay. So I make do with less than perfect shifting (though I use friction shifters), FD sitting way too high. It’s not bad enough for me to bother replacing, either FD, or the cranks. But it is an issue worth noting. 🙂

  17. Hello Rejla,

    i’m kinda stuck with my bike, i tried matching mtb parts with drop handlebar and road brifters.
    The RD is an old deore xt, with 7 speed casette, the FD is a FD-M591, and the cranks are FC-M770 with SM-BB52
    (with spacers in right place). The brifters are ST-3300s. I can’t shift to the smallest chainring, unless i loose some on the in-line barrell adjuster. Could it be unproperly set-up, or the brifter-fd-cranks are not compatible each other?

    Thank You!

    Reply
    • To avoid any misunderstanding:
      ST-3300 are for two chainrings.
      ST-3303 are for three chainrings.

      Cranks are with three chainrings?

      If yes – and the shifters are in fact for 3 chainrings also (i.e. model ST-3303), then I would try tuning/adjusting.
      Inline barrel adjuster makes fine-tuning a lot easier.
      Without one (or even with one, for starting), low end FD limit screw can help in achieving the otpimal cable tension (tightening it a bit more than needed, attaching the cable, then loosening the screw).
      Hmm – I do plan on making a video demonstration on tuning the derailleurs – it’s a bit more difficult to explain all the procedures using words and images. At least for me.

    • thanks! yes, the shifter is for triple speed. I will try to overadjust the lower limit screw, and then reattach the cable. maybe this will help!

    • I tried what You described, but the low end FD limit screw is already all the way in 😀

    • Not sure when I’ll manage to make a video – so only text for now:

      – Loosen the FD shifter cable pinch bolt
      – Adjust the FD low limit screw so that the smallest chainring sits near the inner side of the FD cage.
      – Turn the barrel adjuster all the way in (lowest housing length/cable tension).
      – Pull the cable tightly and secure it with the pinch bolt.
      – Unscrew the FD low limit screw so that the smallest chainring sits in the middle of the FD cage plates.
      – Shift into the largest chainring.
      – Pull the shifter cable by hand, and adjust the FD high limit screw so that the inner side of the FD cage can come a bit closer to the largest chainring (compared to the outer FD cage side), but not too much – to prevent overshifting and having the chain drop off on the outside.

      – Use the barrel adjuster to fine tune.

      If good setup isn’t achieved this way, let me know what exactly the problematic shifts are, and in which positions they occur.
      Generally, if it won’t shift to the smallest chainring, try loosening the low FD limit screw (unscrewing it) further.
      If that too doesn’t help (FD cage stays in place when you unscrew it), then repeat the procedure (as stated above), only this time unscrew the barrel adjuster half way out – so you have more “room” for loosening the cable later. Either that, or start with the FD limit screw a bit less screwed in (so that the smallest chainring is right in the middle of the FD cage, when looking from above).

      Hope I’ve explained the procedure clearly enough.

  18. As you write, it’s easy as 1-2-3 😀
    I’ll give it a try tomorrow, and leave a reply.
    Thanky very much

    Reply
    • It’s me again,
      i just saw your videos on youtube, they’re excellent!

      I’ve followed every instructions, yet I can not find a solution to my problem (either the big or the small chainring was rubbing in front. Until I figured out, the main problem was with the cranks. One day it became eventually loose on the non-drive side, so i loosen the two bolt, inspect the little tab with the security pin (it was not in its designed place) applied some mild force on the drive side to go all the way in, and then installed the nds crank and the security tab, and voilá: after some minor fiddling on the barrel adjuster i can shift all the three chainrings, without rubbing.

      Anyway, keep up with the good work Relja!

    • Hi Bela,

      Thanks for the feedback. 🙂

      Such problems are exactly the reason for making the last three videos on shifting and derailleur tuning.
      Loose cranks, or worn BB bearings are a show-stopping problem that prevents many people from ever getting their shifting perfectly. Not sure how well it’s explained and demonstrated, but I tried my best. 🙂

      Relja

    • Shimano Tiagra 4700 shifters won’t work very well with a Shimano Claris FD.
      Older Tiagra shifters will work.

  19. Hi Bikegremlin,
    Can you solve a problem for me please?
    I have fitted Sora 8 spd triple sti shifters and I can’t get them to work with the XT FD.
    The chainrings are 44/34/26. (Are these sizes the real problem)?
    I have been offered an old Dura Ace FD-7400 which I am told may work. (Although it’s a double).
    Otherwise I have a Sora 9 speed Triple FD?
    Or should I just go with a Sora 8 spd triple one?
    If none of these, then what?!
    The bike is a lovely old Basso lugged bike and I am trying to keep it ‘in the era’!
    Thank you for any help.

    Reply
    • There are several things to consider here. First thing that pops to mind: does FD cage curve fit (follow) the curve of the largest chainring? That’s as far as the sizes go.

      Now, generally speaking: triple FD is more likely to work properly on a triple chainring, than a double FD.
      Also – both 8, an 9 speed road FDs are more likely to work properly with road shifters, than an MTB FD. 9 speed one might have a bit narrower cage, so the 8 speed chain may be more likely to rub when riding cross chained, but that is not advisory anyway, so one could consider that as a “fair warning” to change the gearing combo, more than a problem/malfunction.

      Having said that, Sora FDs are more likely to have their cage shaped to fit a 50 tooth largest chainring, not a 44 tooth one. So in those terms, a matching MTB FD might have an advantage. The problem with those is their cable pull differs a bit compared to the road ones. However, I have used MTB FDs with Sora STI’s with no problems. It isn’t perfect, but it shifts and works. A friend, who is also a mechanic, is having problem with such setup though. Trying to talk him into hopping to my garage, before buying a new FD. If he does, I’ll take a look at it and, if he isn’t in a rush, try to record a video of the (hopefully successful) procedure.

  20. The section on derailleur mounting angle is confusing, as written. In English, (American English, at least) steeper implies more vertical and perpendicular. I would write “Seat tube angle (onto which FD is mounted) is usually about 70 degrees for road bikes, while MTBs usually have a more relaxed seat tube angle, around 65 degrees. If a FD designed for more vertical tube is mounted on a tube that has a more relaxed angle, the effect will be similar to that of placing a smaller chainring designed FD on a much bigger chainring. And vice versa.”

    It might also be useful to make a note that Shimano trekking and MTB derailleurs often come in two orientations, 63-66° chainstay angle (not to be confused with seat tube angle) which is common on road bikes and 29ers… and a 66-69° chainstay angle which is common on older mountain bikes with a 26″ wheel.

    Thank you, Relja, for all the hard work you put into this helpful website!

    Reply
    • Thank you for the feedback – it’s very good.
      I have edited (in fact corrected) the article. I think, thanks to your feedback, it is more clearly explained now (if even a bit more long 🙂 ).
      For laughs: analyzing the mistake – in my native, we use words translated as “sharp” for below 90°, and “blunt” for over 90° angles. Seems I have “switched” the words “steep” and “sharp”, using them as if they’re synonyms in this context, while they have opposite meanings.
      While the angle originally noted for MTB seat tubes was in fact average seat tube to chainstay angle. While trying to make the article less outrageously long, I wasn’t sure whether to use that, or the frame angle. Ended up mixing them – without ever noticing it. Still, with your feedback, I suppose an extra two paragraphs explaining that do a lot more good than harm – for anyone interested in this topic.

      P.S. The amount of high quality feedback (both on the websites and YouTube channel) never ceases to amaze me. Over the years, it has helped make them a lot better, a lot more useful – both to myself (I usually use my websites as a reference/reminder, especially the compatibility and standards articles – can’t keep it all, always, in memory 🙂 ), and, hopefully, the other cyclists/mechanics. Cycling community seems surprisingly supportive, at least in my experience over the past decades.

  21. Hi Relja,
    First, let me thank you for all the helpful info !
    I am doing my first build: converting my 2001 Klein Attitude into a 27,5 Gravelbike. I’m almost there but (of course) it’s the shifting I’m struggling with. I have 3×9 Sora Sti shifters I’d like to use with the existing 3×9 drivetrain (which is still in very good shape). Now the 9 speed front derailleur needs more cable pull than the Sora STi’s offer so it will either not work with or will work poorly I’ve read. I also read I can fix this by

    1. get a 9 speed mtb derailleur and replace the Sora’s with Campa Ergo and go ‘Shimergo’
    2. stick with the Sora’s and 9 speed mtb derailleur and buy a Shiftmate7 from Jtek

    Frankly, I’m not thrilled about option 1 [hassle] nor option 2 [yet another adapter..]

    So I thought about option3 and I’m curious if you think it can work (or better, if you’ve tried it):

    3. get a 3×8 FD like the Shimano FDM310X6. My theory is: because of the slightly larger cage, the lack of cable pull from the Sora Sti shifters will be compensated. You’d start off on the BB side with the left side of the cage at a normal position which would give some extra room on the right side which you need when you shift to a larger chainring.

    Very curious what you think !
    Thanks in advance for your response.
    kind regards
    Wilfred

    PS Looking at the specs the FDM310X6 ticks a lot of the other boxes [chain line, angle, teeth].

    Reply
    • Hello Wilfred,

      If I understand correctly, front shifting is a concern.

      Sora front shifters (all the models up to date) are compatible with any Shimano road FD except the new 11 speed (and the new Tiagra 4700 10 speed ones… and Shimano GRX… see where both me and Shimano are going with this? 🙂 ).
      So any road FD for 3 speeds (different cage shape compared to 2 speed FDs) should work fine.

      Before buying, I would check if it can be configured to work OK with the existing (MTB I assume) FD.
      In case shifter pulls less cable than is optimal, a “hack” I use is to start with the cable just slightly tighter (up to the point when downshifting to the smallest chainring is a bit “lazy/slow”, but still works properly).
      That often gets it just right for the middle chainring, and still fine on the largest chainring, if with some slight chain rub when using the smallest rear sprocket.

      Potential problems with using a road triple FD depend on the cranks. MTB cranks with 28-38-48 tooth count are more likely to work fine with road triple FD-s, generally designed for 30-39-50 cranks.
      On the other hand, smaller MTB cranks, like 24-32-42, are going to see FD cage being too straight for the largest chainring curve. Which can affect shifting, and cause chain rub even when the chain is not severely crossed.

      Bottom line:
      The only really “safe bet” is to buy everything new, matching all the components (which can be both wasteful, and needlessly expensive in my opinion).
      Everything else is a bit of “hacking” – and quality results require a bit more tuning, and also depend on how strict one’s criteria for “OK” are.

      Long ago have I completely switched to friction shifters, never to look back.
      I tune other people’s bikes, especially when they mix-match, but for my own – I prefer something that just works, reliably, always, even if (when) something gets whacked against a tree, or a rock on a ride (I fall down – a lot 🙂 – always keeping it on the edge 🙂 ).

      Regards,
      Relja

  22. Hi Relja.
    Great article, I found it to be very helpful.
    Recently I broke the left shifter of my claris r2000. Im planning to change it to a tiagra 4700 shifter (left only) along with the 4700 fd.
    Would this cause any compatibility problem as I plan to keep the rest of the parts still with my claris.

    Regards
    Nabiel

    Reply
    • Hi Nabiel,

      I’m afraid Tiagra shifters won’t work with the Claris compatible derailleurs (and vice-versa).

      Regards,
      Relja

    • Thanks for the fast reply Relja

      Would the Tiagra 4600 shifter work with the claris r2000 fd?

      Thanks

      Regards
      Nabiel

    • Tiagra 4600 shifters will work with Claris derailleurs. Both the front, and rear (provided a cassette is chosen to match the shifter’s number of speeds). 4700 won’t, but 4600 will.

  23. Hi Relja, I am running a 10 speed setup with hydraulic disc brakes. I have been using RS405 shifters with a 105 5700 rear derailleur and, because the frame is top pull for the front derailleur, I have a CX70 front derailleur. Since my right hand shifter failed recently I decided to go for a set of GRX RX400 shifters, so keeping with 10 speed. I now discover that shimano have changed the cable pull on these shifters to be the same as 11 speed systems. I have purchased a 4700 rear derailleur to be compatible. Can you suggest a top pull front derailleur that would be compatible, or should my CX70 work with the RX400 shifters?

    Reply
    • Just as is the case with the rear, the front shifter will require a “Shimano road 11 speed” compatible FD (not sure how else to name it, since that cable pull is now introduced in 10 speed road, and 10 & 11 speed “gravel”).

      The road FDs work only with bottom cable routing.
      I’m not sure if FD-RX400 is designed for bottom (or dual-side) cable routing. If the frame allows it, a work-around can be done using a cable routing adapter (as shown in the 2nd picture of the 2nd, Cable Routing chapter of this article).

  24. Hi, I have a crappy Mongoose MTB-style bike and I need to replace the front derailleur because it is too worn.

    I’m having difficulty finding anything that will work, and I hope you can suggest a suitable FDR.

    I need 3×7, top-pull, and my chainrings are 52, 34, 24 teeth with a 31.8mm clamp mount. Shifters are twist-type.

    Unfortunately I havent found anything that goes up to 52 teeth with a top-pull that also supports the 28 teeth difference from the largest to smallest chainring.

    I will really appreciate any advice you can give!

    Reply
    • Hello,

      That is a large range in chainring size. For top-pull, unless using an adapter (to effectively make the cable run from the bottom), it limits the choice to MTB FDs.
      However, most MTB FDs are designed for the largest chainring with 48 teeth, or fewer.

      I haven’t tested any with such setup, but if I had to pick, I’d first try with a MTB FD for 48 teeth largest chainring. Shifting may not be perfect, but it could work acceptably well.

      Not even many of those available from the currently produced models (manufacturers are pushing for fewer chainrings up front, and more at the back). I know that older model Acera FDs were made for 48 teeth (as well as some models for fewer, with a “sharper” curve). Not 100% sure about Alivio and Deore.

  25. Hello and great information you offer here.
    I recently purchased a Shimano SLX compact M672 40-30-22 crankset to install on my Novara Mazama, a gravel bike. The problem I ran into was that the back end of the FD cage ( Shimano low clamp SLX ) would hit the chainstay if lowered to the 1-2mm height above the chainring. Is there a FD made specifically for a triple crank with such a small range, or is the problem the frame geometry with more bb drop being the issue, compared to less drop on a mountain bike? What about a 2x FD? I have an 2013 Jamis that runs a 2×11 using a short cage SLX FD.
    Thanks for any insight you can offer.

    Reply
    • Hello Dave,

      …this reminded me of the 2001 A Space Odyssey. 🙂
      When it comes to books and films – that’s my cup of tea. 🙂

      Back on the topic:

      There are a few things to consider. I’ll use numbering for easier reference of any potential follow-up questions. I’ll also write as if you don’t know anything, to avoid any misunderstanding, and in case anyone else with a similar problem reads the question and the reply. You can just skip any redundant info, and please don’t take any offence for some of my stating the obvious stuff.

      1)
      FD cage being 3, even 5 mm above the largest chainring is often OK and results in good shifting, even when using indexed shifters.

      2)
      “Back end” of the cage is the part you described to be hitting the chainstay. It’s a good definition that I’ll use to refer to it, to avoid any misunderstanding.

      3)
      Is the FD cage shaped to follow the curve of the largest chainring (40 toothed one)?
      If not, getting one that is, might result in its cage “back end” being closer to the front part of the bicycle, possibly avoiding the chainstay (since most chainstays are angled “upwards” as they go towards the rear wheel dropouts).
      Not 100% sure I’ve explained this properly. :/

      If the FD cage shape is a matching one, on to the next point:

      4)
      I have a trekking bike frame that was designed for a 48-38-28 crank. Swapped that one for a 42-32-22 one, in order to more easily haul a kid-trailer up steep hills.
      This modification resulted in the same problem that you faced.
      From what I could tell, using a FD with a cage shaped for 40-42 teeth chainring size would still end up hitting the chainstay, or being very, very close – at least on this particular frame.

      Haven’t tested it yet, though. For me, shifting works fine with the FD cage being over 5 mm above the largest chainring. I use friction shifters, so suppose that helps with this.
      And I never seem to find the time to fix my own bikes – there are always some other people’s “in-queue”, and I’m thinking: “don’t touch it while it works,” “I’ll probably swap the cranks for larger ones pretty soon” and so on. 🙂

      5)
      Possible solutions:

      a)
      Simplest, based on point 1): rising the FD to be 3, or even 5 mm above the largest chainring and giving it a try.
      This will, of course, require tightening of the shifter cable (re-clamping it, barrel adjusters won’t allow for taking up that much slack).

      b)
      Based on point 3): getting a matching FD, unless that is already done.

      c)
      Based on point 4): getting larger front chainring(s).
      If memory serves me correctly, there are some 44-32-22 cranks available, so lowest gearing won’t be affected, while it might give that little extra room for the FD cage to completely clear the chainstay while being optimally positioned.

      d)
      Trying a double FD: these don’t work very well with triple cranks.
      Triple FDs can work OK with standard double cranks – the cranks that have up to 14 tooth difference between the large, and the small chainring (such as 53-39).
      Triple FDs don’t work OK with modern compact cranks – the ones that have a 16 tooth difference between the large, and the small chainring (such as 50-34, 52-36, 46-30 etc.).
      The other way round – using a double FD for a triple crank is not very good. Shifting to and from the smallest chainring could be problematic. Chain could be scratching over the rear bottom part of the RD cage when it is on the smallest front chainring and not on the largest few rear sprockets. Also, FD could have problems “convincing” the chain to move from the smallest, to the middle chainring.

      6)
      Final thoughts/notes:

      Many of the “not recommended,” or “borderline” cases depend on the particular gearing, and even frame geometry, i.e: how much does the BB drop relative to the rear wheel dropouts, how long are the chainstays, rear sprocket count, size of the rear and front chainrings etc.

      So I think it’s worth testing the options that are first “on-hand.” Like: if you don’t have a matching FD, or larger chainring, try lifting the existing one by a few mm (in case this suffices) and see how the shifting works.
      Or, if you have a double FD available – it doesn’t hurt to give it a try (preferably on a stand before making a test ride).

      It’s fairly simple – hope I haven’t made it sound too complicated.

      Relja

  26. Hi Relja,
    Once more I would like to ask the PRO guy 🙂

    I am considering to swich from 3×9 (11-34t) to 2×11 (11-46). While doing this I would like to keep the 42 chainring in the front, because it gives me the speed while moving around of the trail. On the other hand to keep the low range of gears I would like to install 28T chainring.
    My present chainring is 22-32-42
    My plans for the new one are 28-42-0
    Here goes my concern: would the FD make the jump from 28 to 42? I guess the books will say NO. But would the experiene say something else? The FD I am using now is FD-M980.

    BTW: The 30 or 32 are still in the game, but I will loose the lowest speeds, I use while climbing those hills around.
    Thank you for any advice.
    Leo

    Reply
    • Hi Leo,

      Digression:
      When people ask about potential changes, or upgrades, my first question is:
      “What is the current setup lacking?”

      1x systems, and even 2x systems do have some advantages over 3x, but it could also be argued (at least for the cyclists who aren’t racing/competing) they are solving a problem that doesn’t exist.
      3x systems can provide a huge gearing range, with relatively small gaps in adjacent gear-ratios, at a relatively budget price and with a good degree of robustness.

      For the FD: anything over 16 teeth difference in adjacent chainring sizes is usually problematic – for 2x FDs. 3x FDs are even more sensitive!
      So, if my calculation is correct, 42 (the answer to life the universe and everything) minus 28 equals 14.
      14 is a piece of cake for any 2x FD worth their salt! 🙂
      3x FDs are at their limit with such a jump, but I would expect even those to work fine. It’s definitely worth giving it a try.
      As long as the FD cage matches the curve of the largest chainring, of course, and is tuned properly.

      Relja

  27. Yes, Relja,
    I know what you mean but asking that question. 🙂
    The thing is that I am running 3×9 for ages. I am unable to set it right for last couple of years. Well, I was trying to solve it (also with your help :)) but even with basically all the involved components new – starting from the shifters, cables, chain, FD, RD, hanger, casette… the problem is still not solved. It must be because of the strange pull ratio of the Shimano 9s system. I read many articles where people got into the same problem.
    The 3×9 is not an option anymore. Shimano doesnt work for me and I do not want to go to SRAM.

    I am considering to get 3×10 with pull ration more 1,2. or 2×11 with pull ratio 1,1.

    Both options will give me gearing range I use to have with 9s sytem. Moreover the 2×11 will save me some troubles during the ascents, when I usually need to change the from the middle to the smallest ring. With 30 in the front and 46 ad the rear I should get what I used to with 22 infront and 34 at the back with 3×9.

    I am still little uncertain, though if all will work if I jut drop the 22 ring and keep 42 and 30 at the place they are now. So now it is 42-32-22 and I plan the new arrangement for 42-32-00. I would rather not go to the 00-42-32 option, because it will create another situation of improvisation.

    What do you think? What would you suggest?
    Thans again, Relja.
    Leo

    Reply
    • Sorry in advance for the long digressions. 🙂

      Gearing can be a bit of a trial-and error. Depending how important the details are.

      3×10 vs 2×11?

      Some people really insist on having 1-tooth size difference across the faster half of the cassette. In that case, more sprockets is usually better.

      When it comes to the total range – I personally have never had any problems using triples.

      Sure – 2x is a bit simpler, no doubt. When racing, and you sometimes need the effort to at least keep the “video” on (“audio” often gets shut down when pushing really hard, at least for me) – not having to worry about cross chaining, or where you are at the front is beneficial in such situations. But for non-competitive riding, even when it is very “spirited,” I’ve never had problems with triples, as long as it’s all tuned properly.

      Digression
      Hell – last problem I had was pushing a half-step double, since 42T smallest chainring is a bit too much for me nowadays, at least on long and steep climbs – but that has nothing to do with any shifters, or derailleurs, it’s a problem with the “engine.” 🙂

      My choice, if changing anything, is robust (2nd hand) friction shifters, and 7, or 8 at the back. But that’s not everyone’s cup of tea.

      Digression
      I’m not sure why you are having problems with your 3×9.
      For example: this long & tedious video is with a Shimano 3×9 hard-working bicycle courier bike. Shifts fine (for) now. 🙂
      I made another video for the really stubborn problems: derailleur tuning show-stopping problems.

      Cranks configuration
      Here my concern would be the chainline. And the availability of chainrings, as well as which sizes can be mounted in which positions on the cranks.
      (if I understood correctly what “42-32-00,” and “00-42-32” mean – I agree and also think that the latter option would complicate things quite a bit)

      What do I suggest?
      Well, I’m really passionate about fixing stuff that doesn’t work. So the first thing I would do is try and fix that 3×9 – if for no other reason, then for curiosity, to figure out why it hadn’t worked! 🙂

      If changing anything, I’d prefer 3×10, because they don’t require the huge (and still often more expensive) cassettes for the really low gearing.
      But this boils down to the above discussed preferences – 2x systems definitely have their pros, as you also mentioned. Plus they look more cool, it has to be said! 🙂
      The thing to consider if going the 2×11 route, while keeping the current 3x cranks, is the chainline. Chain will be at quite an angle when on the largest few rear sprockets (with the “42-32-00,” while 00-42-32 will probably be tricky to put together using the same crank spider). Depending on the cranks, and BB model, as well as the frame, the front chainline can be altered to a degree.

      Hope this helps, more than it confuses. 🙂
      Relja

  28. Yes, it helps, as also your video I watched now. 😉
    Šteta da nisam u Novome Sadu! I would gladly give my bike to your hands, to find that gremlin hidden in there 🙂

    I have a question which came to my mind after I checked my drivetrain once again after watching your video – how about the diference in the measurements of the cassettes.
    Now I have 9s XT cassette which is about 40 mm tall
    Do you know where to get the measurements of the 10s and 11s cassettes?

    I am little bit afraid that I would not have enough space for 10s or 11s cassette. There is maybe only 3 mm left between the cassette and the frame where the axle connects to the frame…
    Leo

    Reply
    • Actually, I just read a very good article about the compatibility of the rear hubs and there is says:

      “10 speed cassettes have even narrower, more tightly spaced sprockets, so their overall width is actually smaller than that of 8 and 9 speed cassettes. That is why placing a 10 speed cassette on a 8, 9 and 10 speed freehub requires a 1 mm wide spacer.
      11 speed MTB cassette is put straight on, just like 8 and 9 speed ones.”

      So I guess, I am safe with both – for 10s I will need even a spacer, though.

      Here is the link to the article, just in case 🙂

      “https://bike.bikegremlin.com/1259/bicycle-rear-hub-compatibility/

      Leo

  29. Is there any problem running a older Dura ACE 8 speed front dérailleur double with the Sora st-r3000 shifter brake lever combo ,Shimano claims only compatible with r3000 front derailleur.

    Reply
    • Haven’t tried that particular combo.
      Would I bet my life on it working perfectly? No.
      Would I give it a try, expecting it to work reasonably well? Definitely!

  30. Thanks for your advice should this combo not work well I have another combo to run by you.Hate to replace the beautiful Dura ace 8 spd fd but if need be have a source for a clamp on Sora 3000 fd.The dilemma is the 52 tooth max chain ring size limit.I’m currently running a campy chorus 9 spd 39/53 crank set ,is this really a problem with just one tooth over max?If so would it be prudent to swap out the 53 outer with one of those beautiful TA vento 52 chain rings.The Campy ones are prohibitively expensive.

    Reply
    • I would be surprised if that 1-tooth difference makes a noticeable difference.

      Regarding the potential chainring swap, I wrote an article explaining the chainring mounting standards. Matching the mounting bolt hole BCD and number (of bolts) is what matters. If that’s matched – the chainring can be mounted and it usually works fine in my experience.

  31. Hi Relja!
    First I gotta say that your service is great and thank you very much for it.
    Now I got a question. Will a Shimano 105 R7000 left shifter work with a shimano tiagra 4700 FD ?
    do i got to take precautions for some other part?
    thanks!

    Reply
  32. hello Relja,

    coudl you please tell me your opinion for the following case :

    I am using Shimano GRX crankset 46/30 + GRX FD RX400 FD . In order to get lower speed I let LBS installed new 3rd party GRX compatible chainrings 42/26.
    However , seat tube has irregular shape and I can not move braze -on FD hanger lower or use any other adapter on the seat tube that would move FD lower.
    so, in result , FD outer cage about 6-7 mm (almost whole difference between 46-42 teeth GRX’s radiuses) above bigger chainring and shifting to higher chainring is very bad, chain is falling down 8 out 10 cases.
    LBS guys told me it will not be perfect as before, but this is not usable at all.
    They have not changed any other FD settings. previously with 46/30 I had never single chain fall for whole season,
    I would think that at least keep 26 or I also have 28 teeth lower chainring installed to let me run easier low-gearing and re-install back original 46 chainring.

    question : do you think that Shimano GRX FD RX400 could handle 26/46 or 28/46 combination ? is it the worth to try to install it or let it be and return back for original 46/30 ?

    Thank you, kind regards, Eduard.

    Reply
    • Hello Edward,

      Digression:
      My “haul-everything” bicycle faces a similar problem. I use friction shifters, which does help, but still – chainstays prevent FD from moving close enough to the chainrings.
      I had to choose between very poor shifting to the largest chainring, or the chain dropping off on the far side – from the largest chainring, towards the pedals.
      For me, swapping for the larger chainrings is an option, but this works well enough, so I don’t bother (I got a good frame very cheaply, and just packed it with the parts I had at hand at the time).

      46 to 26 is a 20 teeth difference.
      I think that even 18 teeth is probably a huge difference for a double FD to handle.
      Would I give it a try with 46-26? If it doesn’t cost an arm and a leg – i.e. if I had the chainrings at hand, so I can swap and test: surely. Out of curiosity, if for no other reason.
      Would I expect it to work well enough? By well enough I mean shifts that take up to one pedal turn. I give it 30 % chance.
      Those aren’t the odds I’d bet my life on, or even a 100 $. But a few dollars and an hour of work? If the lower gearing is important for me – definitely!

      Relja

  33. Relja,

    Do you have any first hand experience or knowledge of the following front mech setup working well?

    Shimano GRX 2×11 Crankset
    Shimano GRX FD-RX810
    Shimano SL-M8000 XT Shifter

    Someone mentioned to me the GRX FD-RX810 has a different pivot point (than previous shimano road FD’s) and the XT shifter’s cable pull may be an issue for the RX810 though it could be fine. As of yet, I haven’t found anything online or anybody’s online post talking about the above setup.

    The bike’s current setup is the above 11 spd GRX Crankset and 11 spd XT Shifter though with an older FD-CX70 10 spd derailleur. The current setup shifts good enough though I would like it to shift better and have another use for the FD-CX70.

    Thanks for any insight and/or experience you may have and keep up the great work on bikegremlin and your videos.

    Reply
    • Hi,

      To help improve this article, before reading the answer:

      Please take a look at the chapter “8. Exceptions,” in this article, and let me know if it answers your question clearly enough?

      The answer:

      As far as I know, it won’t work properly. Shifter lever doesn’t pull enough cable for the GRX FD to work.

  34. Thank you Relja for the quick reply. I had read the section 8 on exceptions but was hoping you may have tested this setup since you last updated that section. As you know Shimano’s official compatibility documentation is fairly conservative and often “unsupported” setups work just fine (i.e., many shops told me the FD-CX70 would not be able to shift GRX cranksets…but it does, just fine). Thanks again…
    p.s., If I decide to test the setup, I’ll let you know the results.

    Reply
    • GRX FDs have the same cable pull ratio as the Tiagra 4700 and other Shimano 11 speed road FDs.
      I haven’t tried combining any of those with different-pull shifters, but I have combined:
      11-speed shifters (Road bike STI-s) with a non-compatible FD (one that requires less cable pull).
      Couldn’t be set properly.
      It worked… very, very remotely OK, in my opinion, and compared to my standards of “really good.”

      Can vice-versa be made to work?
      Using a shifter that pulls less cable than the FD requires.
      I’d be surprised, but I’m looking forward to your feedback.

      What I’d try (if that’s of any help – let me know if it’s not explained clearly):

      0) FD mounting
      Mount the FD to be aligned with the chainrings (cage parallel to the frame’s longitudinal axis).
      Make it stay about 2 mm above the largest chainring. I’ve shown and explained these basics in my derailleur tuning video (starting at 4:59 – to roughly 6:00 – the link should make the video start right there 🙂 ).

      1) Starting position
      Screw-in the low limit screw to push the FD cage a bit more out than is optimal (by about 1-2 mm).
      Tighten the cable pinch-bolt.
      Loosen the low limit screw and see if the FD moves back so it can shift to the small chainring.

      2 a) Loosening the FD cable
      If not, start screwing in the low-limit screw back in.
      Does the FD cage start moving immediately as you start screwing it in?
      If yes, then screw it out by 2 full turns and test the shifting again.

      If not, then stop immediately, screw it back out by half a turn, release the cable pinch bolt, let the cable slide out as the FD moves towards the frame, then re-tighten it again.
      Do this in half a turn increments until it starts shifting to the small ring properly.
      If you have barrel adjusters, then you can go wild – doing one full turn increments! 🙂

      Now you’ve got the cable as tight as possible – since the shifter doesn’t pull enough for that FD, you’ll need that.

      2 b) Tightening the FD cable
      If the FD shifts perfectly to the small ring, then try screwing the FD low limit screw in by half a turn, loosen the FD cable pinch bolt, pull the cable tight, then re-tighten the pinch bolt.
      Until you get to the point where it won’t shift to the small ring properly.
      Once you’re there – you know what’s too much.
      Now, as explained in the 2nd paragraph of 2 a), loosen the FD limit screw by half a turn, release the FD cable pinch bolt, let the FD slide over the cable as it moves slightly towards the frame, and re-tighten the cable pinch bolt.

      In both of these scenarios, you are aiming for the cable to be as tight as possible, while still allowing the FD to shift to the small chainring.

      3) Testing
      Check the downshifts from various chain positions on the cassette. You might see it shifting fine when it’s on the middle, but slack when it’s on the largest cassette sprocket (or vice-versa).
      If it’s not working OK, you’ll need to loosen the cable further – as explained in 2 a).

      4)
      Once the testing is done and you’ve set it to be satisfactory, unscrew the FD limit screw by one turn and leave it at that. It should prevent any chain drop in case the cable snaps, but won’t interfere with the FD movement.

      Also, if you are using a new cable, or new housing (or both), expect the tension to slacken just a little bit after some riding (and shifting).
      So, if you don’t want to re-do the 2 b) procedure, you might want to make the shifting to the small chainring just a little bit “lazy” (“slower than good”).

      5) Outer limit screw adjustment
      Shift to the largest chainring. Without turning the pedals, click the shifter for a down-shift (to release any cable tension).
      Pull the FD cable with your hand, or push the FD directly – to make it move as far out as possible.
      If it moves too far out, tighten the FD limit screw.
      If it doesn’t move far enough, loosen it.
      The idea is to get the FD cage to move just 1 mm further out from being perfectly centred over the largest chainring.

      7) Final touch
      Light a candle, say a prayer to the cycling gods, and see how the shifting works.
      Problems I’m expecting are the FD cage not moving far enough out when the shifter lever is released, after having clicked to shift up.
      While you’re pushing it all the way with your hand, it might keep the FD cage in a good position, but as you release the pressure, it will likely move a bit back, and you’ll get some chain rub.
      Especially when the chain is on the smallest few sprockets in the rear.

      If you manage to get it so-so OK, take it for a test ride and see how it performs “under pressure.”

      Do let me know how it works, and if you’ve faced any problems I couldn’t perceive.
      Good luck. 🙂

      Relja

  35. hi Relja,

    regarding our discussion of GRX FD RX400 chainrings 46/28 – it does not work reliably…keeping this diffrence of 17 teeth is importnat apparently.
    I returned to original 46/30 chainrings.

    anyway, thank you for your time and advise.
    Kind regards, Eduard

    Reply
  36. Pozdrav iz Makedonije Relja,

    Question regarding the Mix I am trying :).
    Currently i have Specialized Sirrus 4.0, Carbon frame with Sora RD, No name FD 48/32 Cranks (no name, but I think its Tourney), Microshift R9 shifters.
    ordered and arriving soon XT SGS M8000 RD, XTR M9000 Right Shifter (all 11 spd). Now, the question remains about the Cranks.
    Option 1 – Would existing 9spd cranks (48/32) work with 11 spd chain (what I have red it says, yes, but one more check – inner width of chain is the same…)
    Option 2 – Shimano GRX 48/31 or GRX 46/30 – Will current FD work? If not, what? (remind You, flat bar shifters 🙂 )
    Option 3 – 1x system with 40 or 42 and 11-46 11 spd at the back – I do not like to be limited with 1x, but if that is only option, so be it.

    Thx

    Reply
    • Pozdrav, 🙂

      I would first try the first option – expecting it to work OK.
      With one note for the “rear end,” just to be sure:
      an 11 speed cassette and an 11 speed chain will be needed for the 11-speed shifter and derailleur.

      Relja

    • Option 1 works like a charm!

      One more addition, during the install i saw that FD is Microshift Centos. I have to say, FD works even better with 11sp chain.

  37. Okay lot of good information! One thing you did not touch on though is total capacity. I’m trying to put together a touring bike with half step plus granny. It is, seemingly, impossible to find a front derailleur that will shift 24-44-48 combination. I currently have an 11 – 32 8spd in back but will probably change to A 13 – 36 nine speed and try to use a double with a 24 / 48. I have resigned myself to modifying the FD cage. I use friction thumb shifter for FD, Index thumb for RD. Fully loaded, I NEED a 24/36 lol. I AM pretty fit… for a 58yr old….

    Reply
    • Hi Terry,

      I did talk about that topic in the 4th chapter (“Double vs triple”) – but it’s probably not stressed clearly enough.

      Relja

  38. Hi Relja,

    Wish I had read this article before buying some components! I appreciate the wealth of information in your article, and also the time that you’ve taken to answer so many questions. I have another question, which I hope you can answer. I recently purchased the GRX 810 FD and RD for a new 2 x 11 bicycle build which I’m pairing with a White Industries R30 crankset. I purchased a 40 and 26 tooth chainring, but now realize that this isn’t going to work with the FD.

    The GRX 810 crank uses a 46/30, and believe that the FD is designed for a minimum top gear of 46 teeth, with a 16 tooth difference. My plan is to use an 11 – 36 or even 11 – 40 cassette. But I’m wondering if I can use 44/28 chainrings in the front? A few teeth lower than minimum but still within the 17t capacity of the FD?

    Appreciate any advice that you may have!

    Reply
    • Hi Tak,

      I’ve had good results with FDs that were up to 2 teeth off, compared to the used chainrings.
      The shifting isn’t perfect, but it does work.

      I’d definitely give that combo at least a try (46T FD, with a 44 T largest chainring).

      With a greater mismatch, it can still work with friction shifters, but with indexed shifters, the shifting gets noticeably sluggish/poor.

      FD capacity is important to mind while mix-matching.
      For double FDs, anything over 16 teeth can be challenging.
      Triples are even more sensitive and have problems with more than 12 teeth difference between adjacent chainrings.

      Hope that helped,
      Relja

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