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Compatibility [04] Rear derailleurs

Updated: 05/01/2021.

This post explains bicycle rear derailleur compatibility, i.e. what derailleurs can work with which number of rear sprockets (cassettes) and which rear shifters. For explanation of other rear derailleur functioning and limitations, such as chain wrap capacity, read this article: Rear derailleur.

Basic terms and what to pay attention to

Most modern bicycles have index shifters, that work with a certain number of clicks. One click per gear change. That is moving the chain from one sprocket/chainring to another with each click.

In order for this to work, these things need to be in tune:

  • Length of cable that shifter pulls/releases with each click. This is called shifter cable pull.
  • Distance that rear derailleur (RD in the remainder of this text) moves laterally per 1 mm of cable movement. This is called rear shift ratio. E.g. if RD moves for 2 mm for 1 mm cable movement (pull or release), then the rear shift ratio is 2.
  • Rear sprocket spacing.

Not directly related to shifter-derailleur compatibility, but it is also crucial to use proper cables and housing. I wrote a post explaining shifter (and brake) cable and housing standards.

When RD compatibility is mentioned, it is all about it’s tune with the shifter cable pull and rear sprocket spacing. When it is all set up correctly, one click of the indexed shifter shifts exactly and correctly one gear (i.e. one sprocket) at the rear. Compatibility will be explained per number of gears and per manufacturer. If it is not noted otherwise, it is understood that shifter make and number of gears match the RD make and the actual number of rear sprockets. There are three major RD and shifter manufacturer standards:

  1. Shimano
  2. SRAM
  3. Campagnolo
  4. Rotor’s hydraulic derailleurs
  5. Table of rear shift ratios for various standards

1. Shimano

6, 7, 8 and 9 speeds

Rear shift ratio is 1.7, that is for 1 mm of cable pull/release, RD is moved left/right by 1.7 mm. Shimano calls this 2:1 ratio for marketing reasons.

All these RDs are compatible and any 6 to 9 speed RD will work perfectly with either 6, 7, 8 or 9 speed shifter. Regardless whether it’s a MTB, or road shifter, or RD. They are also compatible with Shimano 10 speed road shifters, except the Tiagra 4700 series.

Shimano Dura Ace from 1984 to 1996 period (6 to 8 speeds)

Rear shift ratio is 1.9. They are compatible only with Shimano Dura Ace shifters from the same period (that is for 6, 7 and 8 speeds).

10 speed ROAD RD

Rear shift ratio is 1.7, so it’s compatible with all the 6 to 9 speed shifters, as well as road 10 speed shifters. Same rear shift ratio. MTB 10 (and 11 speed) shifters won’t work well.

Exception is Shimano Tiagra 4700 10 speed road RD – it has the same shift ratio as Shimano road 11 speed RDs, so it will work only with Tiagra 4700 shifters and Shimano 11 speed road shifters.

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

10 speed MTB RD

Rear shift ratio of this RD is about 1.2. It is only compatible with Shimano 10 speed MTB shifters and nothing else. Shimano calls this system Dyna-Sys.

11 speed ROAD

Rear shift ratio is around 1.4.  Only compatible with Shimano 11 speed road shifters.

The same shift ratio is used for Tiagra 4700 10 speed groupset, so it’s compatible with it as well, but not with other 10 speed road groupsets.

Rear shift ratio of 1.4 matches old Campagnolo ratio, but I haven’t tested this in practice.

11 speed MTB

Rear shift ratio is around 1.1. Compatible with Shimano MTB 11 speed shifters. Shimano calls this system Dyna-Sys, same as 10 speed MTB, but they’re not compatible!

It has similar rear shift ratio to SRAM 1:1 standard (explained later in this post), so it should match it as well, but I haven’t tried it yet!

11 and 12 speed MTB – Hyperglide+ (XTR M9100)

From summer of 2018 Shimano introduces a new Hyperglide+ 11 and 12 speed MTB standard. It comes with a new XTR M9100 rear derailleur, that only works with a matching shifter (which has an integrated 11, or 12 speed operation switch!) and Hyperglide+ 11 and 12 speed cassettes.


SRAM has four RD families, with 4 different amounts of RD movement per cable movement (actuation ratios). So the only thing to pay attention to is actuation ratio. As long as the RD matches shifter’s actuation ratio (and vice versa), it will work fine.

First, less popular family of SRAM RDs are the ones compatible with Shimano 2:1 standard. Rear shift ratio of 1.7 means they will work with Shimano (and SRAM 2:1) shifters for 6 to 9 speeds (both road and MTB) and road 10 speed ones, except Tiagra 4700 10 speed road shifters.
RDs made in this standard were marketed as 6, 7, 8 and 9 speed models, though this is determined by the shifter – RD doesn’t care how many rear sprockets there are.

Second, more popular SRAM standard is 1:1, with rear shifter ratio of 1.1. This shift ratio is the same as Shimano MTB 11 speed RD (and shifter), so they should be compatible, but I haven’t tested this yet.
RDs made in this standard were marketed as 7, 8 and 9 speed models.

Third, newer standard is Exact Actuation. Rear shifter ratio is 1.3.
Marketed as 10 speed road and MTB , as well as 11 speed road.

Fourth family is X-Actuation, with 1.12 ratio.
Available as 11 and 12 speed MTB RDs 

EDIT: Based on this comment (on this very article) and provided links to SRAM’s website, Exact Actuation and 1:1 are the same thing. Will have to measure, check and confirm this.

3. Campagnolo

Campagnolo has two standards of rear shift ratio. Old 1.4 and new 1.5. Also, not every shifter pulls the same amount of cable with each click. With 10 speed for example, there is more cable pull for “slower” speeds, than there is for the others.  2.5 mm pull five times (from smallest 1st to the 6th sprocket), 3 mm for 7th and 8th, then 3.5 mm for 9th and 10th. 2.83 mm average cable pull per click.  🙂

Apart from that, as of 2014 (don’t take my word for the exact year), campagnolo introduces another 11 speed standard. Previous Revolution 11 and the newest Revolution 11+. They are not compatible.

Since Campagnolo cassettes sprocket spacing differs from other manufacturers’, it is hard to combine Campagnolo RDs with anything but the appropriate Campagnolo shifters and in most cases cassettes too.

In 2018, Campagnolo introduced their own 12 speed standard – not compatible with any other.

4. Rotor

Rotor’s hydraulic rear derailleurs are only compatible with their hydraulic shifters.

5. Table of rear shift ratios for various standards

Shimano standard – 1.7SRAM 2:1 – 1.7Campagnolo old – 1.4
Shimano 10 MTB – 1.2SRAM 1:1 – 1.1Campagnolo new – 1.5
Shimano 11 road – 1.4
* Including Tiagra 4700 10 speed road
SRAM Exact Actuation – 1.3Campagnolo Revolution 11+ – N/A
Shimano 11 MTB – 1.1SRAM X-Actuation – 1.12 
Shimano Dura Ace 6 to 8 speeds – 1.9  

Related post – Bicycle rear hub compatibility:

Compatibility of bicycle rear hubs - which can accept what kinds of sprockets (cassettes)
Compatibility of bicycle rear hubs – which can accept what kinds of “sprockets” (cassettes)

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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113 thoughts on “Compatibility [04] Rear derailleurs”

  1. Hi ,
    I am looking to replace my Shimano 105 RD-1050 . One of the links is broken. I am told a Claris RD-2000 SS 8 speed derailleur will work . I was wondering if a Sora RD-R3000-SS 9 speed derailleur would work or even a 105 RD-5701 ?

    • Shimano 105 10 speed RDs (5700 series) is compatible with Shimano road and MTB RDs for up to 9 speeds (among other compatibilities), so it should work fine.

      So would the Sora 9 speed RD. And the Claris RD.

    • With the combinations I’ve tried, at least 2-speads fewer on the chain than what they are on the derailleur, there have been no problems (like 7 speed chain on 9 speed derailleurs).
      Haven’t tested the extremes, like a 6, or a 7 speed chain on an 11 speed derailleur. If I had an 11 speed RD laying around, I’d mount it and test, just to know. 🙂

    • Hi,

      I just finished the upgrade on my older Peugeot steel bike bike. It already had Shimano 105 group but it was a 6 speed free hub and the rear derailleur link failed so had to be replaced. Upgraded from a 6 speed free wheel to an 8 speed cassette on a new rear wheel. I used a 10 speed RD-5701 with an 8 speed cassette / chain and had an old Sora 8 speed shifter. Works great !! I bought an extra rear 105 10 speed derailleur ( just in case) since they seem to be phased out and the 11 speed have a different ratio 1.4 instead of 1.7 .

      Thanks for you help. None of the bike shops mechanics I spoke to said it would work . Great info here and proved it does work .

    • Glad to hear it has helped. 🙂

      Sourcing (new) parts is both complicated/difficult and rather expensive compared to average local pays in my country.
      So we have to find ways to improvise with most things.

      A lot of the combinations I have tried and confirmed to be working are against manufacturers’ recommendations.
      I believe manufacturers make recommendations a bit more “strictly”, both in order to avoid any potential law suits, and to make more profit – “forcing” people to buy the new stuff.

      As far as mechanics go – it makes sense for them to recommend what manufacturers recommend – to avoid any complaints, or law suits.
      Also, it is practically impossible to keep track of all the different systems and “standards”. The word “standard” has become meaningless in the cycling industry, since even one same manufacturer keeps making new stuff to be incompatible with the old stuff.
      I write everything down, but most “normal” mechanics I know are not as inclined to do so (I’m a systems administrator, working on bikes as a hobby). So even in my city, even though colleagues know about my website, I get a call from time to time about certain combinations – “just to check with you if it would work”. 🙂

      Wouldn’t blame the mechanics – it’s the industry, the manufacturers, that is making things as difficult as possible.
      With the discontinuing of good quality older stuff, as you mentioned – practically forcing us to “shut up and buy newest stuff”.
      I find that unreasonable, not very eco-friendly, and probably not very good for the industry in the long run. As a mechanic, for bottom brackets alone, one needs about 10 different tools now. Same complications face home mechanics, in case they get a new bicycle, or have more than one bicycle, from different eras. Training staff at shops also takes a lot more time, because of a huge number of different, incompatible parts. It seems to be getting worse every year.

      Anyway – sorry for the long rant/explanation – the bottom line is, it’s normal, in my opinion, even for good and competent mechanics, to not know everything.

  2. @Relja, so based on the compatibility information you provided, my bikes that run Shimano Dura Ace 7900 10-speed and 105 5700 10-speed shifters would work with the older Dura Ace 7700 9-speed rear derailleur?

    • That’s what think as well.
      The total number of permutations is huge (all the RD models times all the shifters times the number of rear cog combos).
      Si no way for me to test and confirm every possible combination.
      Which is why I noted all the pull ratios – so I too can easily see what matches with what (even when there is a slight mismatch, it’s often worth a try). In the combo you mentioned it is a 100% match for all I know and I’d give it a go.
      In other words, I’m yet to find a combo that should work by my charts, and doesn’t work in practice – if I do, will make sure to correct the provided info.

  3. Hi there
    I am converting a road bike to hybrid. So looking for a 9 or 10 speed twistgrip shifter that will work with a Shimano Ultegra road bike derailleur. I know something like the Shimano SL R770 thumb shifter is widely recommended but I specifically want a twist shift. Is this possible? Thanks.

    • This should work with Shimano Ultegra rear derailleur, unless it’s an 11 speed one (so, works with 10, 9, 8…):
      Grip Shift 3×9 Shimano compatible shifters
      (Amazon affiliate link)

      Haven’t tried that particular model, but it’s what I could Google that is grip shift, and works with Shimano RDs.

      SRAM grip shifters are more widespread, but most would require a compatible (SRAM) rear derailleur.

    • If it is in fact 2:1 (the Shimano compatible), then it will work with all the Shimano rear derialleurs for 9 and fewer speeds, as well as with 10 speed Shimano road derailleurs, except Tiagra 4700.

  4. Running campy 10’s shifters with 11’s shimano der. & 9’s Shimano cassette
    Works spot on, This would make derialleur more like 1.5 ratio ??
    as I agree with pull ratio average

    • Or the shifter cable pull is not (completely) accurately measured.
      Also, for Campagnolo 10 speed shifters, cable pull differs along the stroke – increasing as the gears are changed towards the larger sprockets.
      I’m not able to measure 100% accurately, and tell whether it is similar with Shimano as well.
      The fact that manufacturers don’t publish the data isn’t helping either.

      Might find this discussion interesting:
      Rear shifter compatibility discussion

  5. Thank you! This is the most useful page of rear derailleur pull ratios I’ve found. And I’ve been looking.

  6. Hi, this sounds pretty straightforward. However, I have a Shimano DA 7700 9x shifter and the manual states explicitly that it can ONLY be used with Dura-Ace derailleurs. If all Shimano groups sub 10x have basically the same pull ratio, why could that be? Currently I use it with a Deore 9x and it doesn’t work well for all gears. Searching for an alternative.

    thanks in advance, Ralf

    • Hello,

      – Short answer –

      I’m not sure, don’t know.

      – Longer answer –

      As far as I know Dura Ace has different cable pulls for older 6 to 8 speed systems (as noted in this article), while 9 speed DA RD has the same cable pull/movement ratio as the other Shimano 9 speed RDs. However, I haven’t tried the combo so can’t 100% confirm it.

      On the other hand, Shimano is quite conservative with their compatibility charts, so many combos that I’ve tested and confirmed to work well, are not recommended according to their compatibility charts.

      – Even longer answer –

      I still haven’t made a detailed article, nor a video on derailleur tuning, but shifting problems can be due to many different factors, such as:
      – cable and housing quality, choice and routing
      – RD hanger alignment (“straightness”)
      – B-screw, and H(igh) and L(ow) limit screws setup
      – Chainline
      – Chain and/or cassette wear
      – Shifter and/or RD wear/damage

      These things are sometimes missed even by experienced mechanics. The term: “not seeing the forest from the trees” comes to mind.

      So it might, but it might not be due to any RD incompatibility. The exact troubleshooting procedure also depends on when (pedaling hard, pedaling normally, or also on the working stand), and in which gear combos the problems occur.


  7. Hi Relja,

    I am planning to make a partial upgrade for my RB due to budget constraints. I am using a 9-speed shimano sora gear set and wondering if I can start upgrading to a 105 gear set by replacing each components one/two at a time, eg: sprocket and RD, and then FD and crank set, and then brake/shifter and so on.

    Thanks in advance

    • Rear shifting: if 105 is a 10, or 11 speed group (the newest one is 11 speed), then shifter, derailleur, and cassette need to match each other. So those three must be installed “in one go”.

      Rear wheel: 11 speed road cassettes also require a different (wider) freehub.
      Note: this makes the rear wheel weaker, since it is severely dished to one side. For example: Mavic Aksium rim with an 11 speed road freehub requires right hand side spoke tension to be around 160 Kgf, in order for the left hand side spoke tension to not go below (rather slack) 60 Kgf (and so they don’t go loosening over time). It’s crazy, in my opinion.

      Front shifting: front shifter and derailleur for 11 speeds also need to be matched. 10 speed 105 front shifter will work with the current FD, and vice-versa.

      Cranks are most likely to work with either setup.

      Finally, a more “philosophical” thing: what are the problems with the current setup? What is it lacking? In other words: what is the goal of the upgrade?
      Those are the things I usually suggest people ask themselves before deciding on any upgrades.

    • Wow, thank you for the insight. I never actually thought about the 11 spd hub will make the rear wheel weaker but it does make sense.

    • Wow thanks for the insight. I would never thought the 11 spd hub will make the rear wheel weaker.

      My current setup has start making noises here and there and basically I just wanna treat myself to an upgrade LOL.

    • I plan on writing an article about the whole “upgrades” and “future proofing” topic. It is what many people ask and consider. Hopefully within a month I’ll get it done – hectic schedule this summer.

  8. Your edit/update links to a comment about 1:1 vs. Exact Actuation but it didn’t seem to work. It is confusing, but 1:1 was used to market 9-speed and older stuff. and Exact Actuation came out for 10s road and mtb and had a different cable pull. It’s still 1:1 but not compatible with the older 1:1 stuff. Cable pull changed, but the derailleur movement also changed, so it still can be 1:1, if that makes sense. Hope that helps. Thanks for a useful article.

  9. Hello Relja, good day to you.

    Could You please advise me :

    I am having gravel bike with Shimano rearhub SHIMANO TIAGRA HB-RS470 (10/11 speed), Shimano GRX 10 speeds shifters and also RX-400 10 -speed rear deraileur, working on Shimano 10 speed 11-42 cassette. Even max. range for derailleur is declared 11-36 only , it shifts nicely to 42 – just by setting without any further components.

    Once existing cassette is worn -out, I speculate on the following:

    as I do not need 11th cog – too fast for me/almost never used, I evaluate possibility to use 11-speed cassette 11-42 (pricewise not much different from 10-speed) so , to mount it on existing hub and re-use the existing shifters and rear derailleur….
    As I would use only 10 cogs from 13-42 range, leaving 11-th cog not used.
    As the Tiagra hub is usable for 11 speed as well , and you say that GRX 10-speed and Tiagra rear deraillaurs are having the same shift ratio as 11-speed rear derailleurs….would it work ? or , where am I doing wrong assumption ? 🙂

    Thank you for advise

    • Hello Eduard,

      From what I could gather (you’ve provided all the relevant info in the comment):

      11 speed cassettes have different pitch, compared to the 10 speed ones (see the table in the cassette compatibility article). So I would not expect such setup to work without using 11 speed shifters (and 11 speed chain – see chain compatibility article for the explanation why).

      The problem with cassettes being sold starting with 11, maximum 12 cogs (apart from super-expensive road cassettes marketed for “junior racing”) is something that doesn’t cease to amaze me.
      Most people I know don’t really spin out 48, or 50 – 11 combination. Sure, it can be used to add some speed on a descent, but I’d much rather ride 53-39 with a 14-34 cassette, than 34-50 with 11-28 (or 11-34 one for that matter). Apart from a bit of extra weight, drivetrains with more teeth involved last a lot longer. And make much more sense (at least in my opinion, for recreational riding).

      Not to mention that 11-42 cassette could be avoided if they continued to make triple front chainrings, for road, and MTB groupsets (they can still be sourced, but only for the “lower end” stuff).

      So, unfortunately, we all end up with a few unused sprockets, and chain more crossed when riding on the big chainring. Industry, marketers, and many buyers seem to love this. I have no other explanation.

  10. hello Relja,

    thank you for prompt reply and useful info.

    however, I would like to ask you if (at least) i could replace the smallest cog on mine cassette 11-42, which is CS-HG500-10 10-speed by
    new 12T sprocket of the same type cassette – HG500
    I found on Shimano support pages that :
    Sprocket Wheel 12T (Built in spacer type) for 12-28T – in their nomenclature = Y1Z81201N would pass to 12-28 cassette…
    Mine GRX RX400 10-speed derailleur smallest cog is declared 11T, however I do see sufficient distance between 11T cog and RD now and I suppose it can handle 12T bravely.
    The cost is not so high – about 7 Euro + I would have check delivery with Shimano dealer in SVK to minimise shipping costs.
    anyway, there are specialized sites for such ” little things” e.g. in Germany, however shipment is rather high.
    Do you think – will it work=shift properly/smoothly ? Will not these splines on the newest technology cassettes somehow interfere ?

    Thank you for reply – have a good day
    Kind regards

    • What Fabrice said – you will need a (slightly larger than 11) lockring for 12T sprocket.
      Apart from that, since you are swapping the smallest for another smallest sprocket, I would expect all the teeth to be perfectly aligned and shifting to be as good, if not better (since the jumps in tooth count from the smallest to the 2nd smallest will be reduced – 12 to 13 I suppose).

  11. Hello Eduard,
    It will be OK. I’m not sure whether the shifting will be just acceptable or perfect, though.
    Anyway, you will also need a lockring for 12T cog.

  12. Hi guys,

    indeed – this one :

    Y1RB98020 Lock Ring for 12T Top Gear

    thanks for reply.

    well, I have just to count expenses if it is really value….
    2 x items , each about 7-8 euro + shipment, mhmmm…for only slightly lower gearing.
    will see…better if man could customise cassette under such supplier conditions…no such option found by me .
    Sometimes Miche was offering this, however not up to 12-40/42 …
    Thank you
    kind regards

  13. Has anyone tried using a 10 speed Dyna-Sys shifter with an exact actuation 10 speed sram rear derailer? The ratios are close 1.2 and 1.3 respectively, surely it would mostly kinda work?


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