Bicycle rear shifter compatibility

Compatibility [07] Rear shifters

Updated: 07/10/2019.

Rear shifters are of course used to shift gears at the back – that is to control the rear derailleur (RD in the future) which then moves the chain from one rear sprocket to the other. In this post, first there will be a short explanation of difference between friction and indexed shifters, then the compatibility of indexed shifters will be explained by three standards of the three biggest equipment manufacturers: SRAM, Campagnolo and Shimano. For each standard, it will be sorted by the number of “speeds”, that is the number of rear sprockets.


Friction vs indexed shifters

This goes for both front and rear shifters.

Friction shifters work analogously – that is the cable is pulled for the amount that the lever shifter is moved. Changing gears is done by feel (and hearing) – moving the lever until the gear is changed and chain rattling stops. 🙂

Advantage of such system is that it always works without fine tuning. It is the most robust shifter system. Disadvantage is that it is sometimes harder to get it just right manually – it takes some time and practice. They are compatible with all the RDs and numbers of speeds, but if there are more than 8 sprockets at the back, sprockets are more tightly packed, closer together, so it is hard to get the RD to align with the desired sprocket – smaller error margin. That is why they can’t be recommended for more than 8 sprockets.

Indexed shifters have a number of pre-designed positions. One click moves/releases cable by a certain, pre-calculated amount. Number of clicks needs to match the number of rear sprockets (minus one, of course) and the amount of cable pulled needs to move the RD to align with the next sprocket. Additional complication is that various models of RDs move for various distance for the same amount of cable pulled (for 1 mm of cable pull, some RDs move for 1,7 mm, while others move for only 1,3 mm etc.). This needs to be considered when talking about compatibility.

In the rest of this post, it will be explained which indexed shifters can be mixed with which RDs. If it’s not noted differently, it is understood that the number of shifter speeds matches the number of rear sprockets (10 speed shifter with a 10 speed cassette and so on).

Number of speeds RD is designed for is more a marketing term – as long as RD movement and desired cable pull is matched with the shifter cable pull, all will work fine.


Important note

This goes whenever combining shifters with more speeds than the number of rear sprockets. For example: 7 speed shifter with a 6 speed cassette and similar.

Shifter will have more clicks than there are available rear sprockets. To prevent shifting to drop the chain off the cassette, RD movement needs to be limited with limit screws (this should always be done anyway, regardless of the shifter used).

When the chain reaches the end of the cassette, shifter will have more clicks. Every indexed shifter has clicks for releasing and for pulling the cable. When setting up the shifter, it should be set up so that it can pull the cable all the way, leaving one or more click for releasing the cable unused.

For example, 7 speed shifter with a 6 speed cassette should be set so that when it pulls the maximal amount of cable, the RD aligns with one end of the cassette, and after five clicks of cable release RD should be aligned with the opposite side of the cassette. This leaves sixth click for releasing the cable unused – RD will not move at all, since it will be limited with limit screws.

Opposite setup would be so that when cable is released as far as it goes, RD aligns with one end of the cassette. Then, after five clicks for pulling the cable, RD will reach the opposite side of the cassette and the limit screw stop. This will leave one more click for pulling the cable available. Shifter lever will allow one more click for pulling the cable, while the RD will be stuck in place with the limit screw. If shifter lever is pulled for the remaining click, probably nothing will happen but the user will feel the lever not moving, resisting. However, since shifter mechanism is fine and sensitive and the RD can not move any more, pulling the lever could cause the shifter mechanism to break and shifter will no longer work.

Reminder: if RD movement is not correctly limited with limit screws, it could “change” a gear so that chain drops off the sprockets completely, which can be a problem.


a) SRAM

SRAM shifters come in four different standars:

  • Shifters compatible with “Shimano 2:1” standard. They come in versions made for 6, 7, 8 and 9 speed cassettes.
  • SRAM 1:1 standard. They come in versions from 7 to 9 speeds.
  • SRAM Exact Actuation. Available in 9 and 10 speeds for both road and MTB (shifter lever ergonomy differs for flat MTB and drop road bars), and in 11 speeds for road only.
  • SRAM X-Actuation. So far only MTB 11 and 12 speeds versions are available.

Each of these shifters works fine with any SRAM RD as long as they are by the same standard.

In addition to that, shifters compatible with Shimano 2:1 standard can work with Shimano MTB RDs for 6 to 9 speeds and with Shimano road RDs for 6 to 10 speeds. Exception is Shimano Tiagra 4700 10-speed RD series – these will not be compatible.

SRAM 1:1 is, judging by data, compatible with Shimano 11 speed MTB RDs, but I haven’t tested this in practice.


b) Campagnolo

Campagnolo has two standards per shift, called old and new. 🙂  Old ones are matched with old RDs, new ones with new. Since the amount of needed cable pull differs for each number of rear sprockets, there is no cross compatibility whatsoever. 10 speed new shifters work only with new 10 speed RDs. 8 speed ones with 8 speed RDs. And so on. Old standard comes in 8 to 10 speed variants, while the new one comes in 9 to 11 speeds.

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.

One exception is that old Campagnolo standard, judging by data, should work with Shimano 11 speed road RDs, but I haven’t tested this.

Other exception are the new Campagnolo 10 speed shifters. They can work with Shimano RDs for 6 to 9 speeds (and old Shimano road 10 speed RDs) and Shimano 8 speed cassettes. Cable pull of Campy 10 speed shifters is not the same for every gear change, there will be two unused shifts with an 8 speed cassette, but it can be made to work satisfactory.

If it is any consolation, Campagnolo shifters are more robust, longer lasting and can be serviced, unlike other manufacturers’ shifters.

It is also interesting that not every Campagnolo 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.  🙂


c) Shimano

Compatibility will be given per number of speeds, except for 10 and 11 speed shifters, where cable pull differs from road to MTB models.

6, 7, 8 and 9 speed shifters

Combining with various RDs:

Shimano shifters, whether for 6, 7, 8, or 9 speeds are compatible with all the Shimano RDs for 6 to 9 speeds, and with Shimano 10 speed road RDs (not with 10 speed MTB RDs).

They are also compatible with SRAM 2:1 RDs (that were in fact made so that they match the Shimano standard).

Combining with various rear sprockets:

6 speed shifters will work well with 7 speed sprockets, but they will not shift onto one of the outer sprockets because they don’t have enough “clicks” (5 in stead of 6 needed for a 7 speed cassette). They can be set up so that they don’t shift onto the smallest, or the largest sprocket at the back, with everything else working fine.

7 speed shifters will work with 6 speed sprockets, but one “click” will be unused – will do nothing (read the important note at the beginning of the post if doing this).

They can also be combined with 8 speed cassettes, but some gears might not work perfectly and there will be one unused sprocket at one end of the cassette, or the other. Similar goes for pairing 6 speed shifters with 8 speed cassettes.

8 speed shifters can work with 6 and 7 speed sprockets (read the important note at the beginning of the post if doing this). Since the required Shimano 8 speed cable pull differs slightly from the 6 and 7 speed one, shifting will not be as quick, accurate and there might be some chain noise in certain gears, but most will work fine.

9 speed shifters pull significantly less cable per click than 6, 7 and 8 speed ones. They can be combined with 6 to 8 speed sprockets (read the important note at the beginning of the post if doing this) if the cable is attached to the opposite side at the RD (see position B in the picture below). Then it will all work , but some gears might not work perfectly.

Alternative cable attachment. Position B will cause RD to move more, which helps if shifter doesn't pull enough cable.
Alternative cable attachment.
Position B will cause RD to move more, which helps if shifter doesn’t pull enough cable.
Source: www.sheldonbrown.com

A “hack” if a shifter pulls more cable than it should, when mix-matching, is shown in the picture below, but I haven’t tested that:

Attaching cable in the C position will cause the RD to move a little less per 1 mm of cable pull, than it's "factory" default design
Attaching cable in the C position will cause the RD to move a little less per 1 mm of cable pull, than it’s “factory” default design
Source: www.sheldonbrown.com


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

Shimano Dura Ace shifters for 6, 7 and 8 speeds will only work with Shimano Dura Ace RDs for 6 to 8 speeds. That means each shifter will work with each RD, as long as they are Dura Ace and built in the period from the heading (that is 6 to 8 speeds).


10 speed ROAD shifters

Combining with various RDs:

Shimano 10 speed road shifters are compatible with Shimano MTB RDs from 6 to 9 speeds and with shimano road RDs from 6 to 10 speeds.

Exceptions are Shimano Tiagra 4700 road shifters that work with Shimano Tiagra 4700 RDs and Shimano 11 speed road RDs.

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

Combining with various rear sprockets:

With alternate cable attachment (position B in the picture above), they can be made to work with 9 speed cassettes. Shifting speed and precision will degrade, but it can wok.


10 speed MTB shifters

They can only work with Shimano 10 speed MTB RDs.


11 speed ROAD shifters

They work with Shimano 11 speed road RDs and with Shimano Tiagra 4700 10 speed road RDs.

By data, they should also work with old Campagnolo RDs, but I haven’t tested this. Old Campagnolo RDs come in 8, 9 and 10 speed variants. They should work with 8 and 9 speed old Campagnolo RDs, as long as the cassette used is Shimano 11 speed road one.


11 speed MTB shifters

They work Shimano 11 speed MTB RDs.

I haven’t tested, but they should work with SRAM RDs of SRAM 1:1 standard. They should work, as long as the cassette used is Shimano 11 speed MTB one.


New 11 and 12 speed Hyperglide+

From summer of 2018 Shimano introduces a new XTR M9100 groupset. New shifters have a switch for 11 and 12 speed operation setup, but only work with new Hyperglide+ cassettes.

Table
Shifter type – amount of cable pulled with each click in mm

For 10 and 11 new Campagnolo, this differs from click to click, the data is given on average.

Shimano 6 – 3.2SRAM 2:1 n = Shimano nCampagnolo 8 – 3.5
Shimano 7 – 2.9SRAM 1:1 7 MTB – 4.5Campagnolo old 9 – 3.2
Shimano 8 – 2.8SRAM 1:1 8 MTB – 4.3Campagnolo new 9 – 3
Shimano 9 – 2.5SRAM 1:1 9 MTB – 4Campagnolo new 10 – 2.8
Shimano 10 road – 2.3SRAM Exact Actuation 10 – 3.1Campagnolo new Revolution 11 – 2.6
Shimano 10 MTB – 3.4SRAM Exact Actuation 11 road – 3.1 * Campagnolo Revolution 11+ – N/A
Shimano 11 road – 2.7SRAM X-Actuation 11 – 3.48 
Shimano 11 MTB – 3.6  

* Most probably incorrect number, needs checking. Can’t be the same as 10 speed Exact Actuation, since cassette pitch is different (narrower).

Related post – Bicycle groupset (equipment):

Bicycle groupset (drivetrain)
Bicycle groupset (drivetrain)

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

Bicycle Drivetrain Compatibility on Amazon
Bicycle Drivetrain Compatibility on Amazon
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15 thoughts on “Compatibility [07] Rear shifters”

  1. Can I match a Shimano 10s Road shifter, a 9spd Shimano MTB long cage RD and a Shimano 10s MTB cassette? (I’m trying to put 11-34 gearing on my 10s road bike) I understand how to make sure the chain is sized correctly and the limit screws are adjusted properly.
    Thanks!
    Jim

    Reply
    • Short answer: It will work unless the shifters are Tiagra 4700 10 speed ones.

      Longer answer (explanation):

      Several components to look out for here. Will use exclusion method – one by one.

      Shimano 10 speed cassettes have the same spacing both for MTB and Road – so that part is OK. Wrote about it in more detail here:
      https://bike.bikegremlin.com/1232/bicycle-cassette-compatibility/

      As for shifters (and their function with the RD): unless the shifters are Tiagra 4700 10 speed, they will work (any other older 10 speed road shifters are compatible, but not the newest Tiagra 4700).
      So 10 speed 105, Ultegra etc will work fine.

      In order to improve this article, is that part not explained clearly enough in the chapter: “10 speed ROAD shifters” of this article? English is not my native – was any sentence not clear enough, or contradictory with other sentences? “Return information” and suggestions are very helpful.

  2. It’s written that friction shifting is not recommended for more than 7 gears. However if you use a SRAM exact actuation RD you get again 3.1mm per gear. I drive 9 gears with an exact actuation RD and friction shifting and it works pretty well.

    Reply
    • I agree. The longer-cable-pull RD-s are easier to operate using friction shifting (and less susceptible to any housing/cable imperfections when used with indexed shifters).

      Not sure who recommends no more than 7. For example, I draw the line at 8 – though, as you noted, with longer cable pull RDs it can work fine with 9, some use it even with 10.

      Having said that: the fewer the sprocket number, the better/easier friction shifting (and the higher indexed shifter system “robustness” to any housing/cable imperfections) – all else being equal.

  3. Hi, I was just wondering, with all the craze on clutched rear derailleurs for 9 speed MTB transmission, why has nobody gone with a SRAM 9 speed shifter and a 11 speed shimano rear derailleur? I’ve seen many people pair the SRAM 9 speed shifter with a 10 speed shimano rear derailleur, but from the cable pull ratios mentioned in the artscyclery drivetrain compatibility page, 9s SRAM shifter and 10s shimano rear derailleur should not be shifting smoothly.

    https://www.artscyclery.com/science-behind-the-magic/science-behind-the-magic-drivetrain-compatibility/

    From the charts, for SRAM 9 speed shifters and shimano 10 speed derailleurs, we have:
    Cable Pull: 4mm
    Derailleur Ratio: 1.2
    Calculated Cog Pitch: 4.8mm
    vs Measured Cog Pitch (% difference): 10.34%

    Pretty big if you ask me. But I’ve noticed something else. Why has nobody paired the SRAM 9 speed shifters with 11 speed shimano derailleurs? The cable pull looks bang on! Lets explore this:
    Cable Pull: 4mm
    Derailleur Ratio: 1.1
    Calculated Cog Pitch: 4.4mm
    vs Measured Cog Pitch (% difference): 1.15%

    Sees extremely viable from my point of view, what do you guys think?

    Reply
    • A very, very good question.
      I think your calculations are correct.
      This should work OK. There is no 100% alignment (as you calculated), but there’s a lot more cable pull per shift than with using all Shimano 9 speed setup (shifter and derailleur).
      So, in theory, it might be quite good. Haven’t tried it though so I could confirm.

      It should definitely work better than the SRAM 9 1:1 shifter and Shimano MTB 10 speed RD.

  4. Hi Relja, just an update.

    I borrowed an XTR M9000 GS rear derailleur from my mate and put it on my bike using a SRAM X7 9 speed trigger shifter together with a sunrace 11-40T 9 speed cassette.

    It works great but I had to dial back the clutch force as shifting up was pretty stiff. I think the shifter wasn’t made for clutch derailleurs, thus the difficulty.

    Apart from this, the shifting was great, I also managed to take a video of it indexing through all the gears. Let me know if you want it.

    Reply
    • Hello Dennis,

      First I’d like to thank you for this information – it’s a great contribution that will help any mechanic and mechanics enthusiast. 🙂
      In those terms, I think the video of the setup could only help, can’t do any harm. Comments containing links often get caught by spam filter, but I’ll make sure to check and (“manually”) approve the publishing, if needed.

      About difficulty when shifting up with the RD clutch “enabled”. Just to confirm we’re thinking of the same thing: shifting “up” – as when pulling the cable?
      If that is the case, my thinking out loud:

      11 speed RD is intended to move for a shorter amount per click, than the 9 speed shifter tries to move it (9 speed sprockets are more widely spaced).
      Vice versa: 11 speed shifter pulls less cable per shift – that is: per similar movement of the lever. Which boils down to it having more mechanical advantage than a 9 speed shifter, making it easier to move a clutch derailleur.

      Mechanical advantage in more detail, explained in terms of brakes:
      https://bike.bikegremlin.com/1419/bicycle-mechanical-brakes/

  5. Hi!
    I have a 10speed 700c rear wheel and I was wondering if I could make it work with a old Fiji 5 speed bike that operates via paddle shifters. I want to use it as a commuter bike.

    Thanks ahead of time!

    Bests,

    Sky

    Reply
  6. Same as Dennis above. Fitted 11s Shimano ST505 shifters (similar enough cable pull as 9 speed) with 7-10sp RD5700 rear derailleur with 9 speed cassette. This was to be able to use hydraulic brakes on a road bike.
    Worked fine just had to close out the upper gears. Saved on purchasing 11 speed wheels.
    Although if using 11s 28t or above cassette you can machine 0.85mm off the back of the cassette to use 11sp cassette on 10sp wheels.

    Reply
    • Hi Phil,

      Thanks for the info – and sharing a great workaround for getting the hydro brakes and levers to work, while keeping an “older” drivetrain.

      The RD movement ends up being just a little bit greater than ideal, but if using RD limit screws correctly, one should be able to make it work – as you apparently have.

      With the RD position probably ending neary 100% spot on aligned with the mid part of the cassette – that often gets mostly used, especially with 2x and 3x cranks, as well as on the largest and smallest sprockets (thanks to the RD limit screws).

  7. I don’t get it, could you please explain. I’m on a small budget and i plan on changing a lot of parts on my old bike.

    My current drive train:
    -6 speed freewheel (generic brand)
    -7 speed rear derailleur (a shimano rd-tz30)
    -6 speed shifter (generic brand but shimano compatible)
    -3 speed chainring (with a chainring derailleur that works fine)

    I’d like to have this drivetrain
    -replace the freewheel hub with a freehub
    -9 speed cassette (either a shimano or shimano alike)
    -9 speed shifter (shimano compatible)
    -keep my 7 speed rear derailleur
    -keep my 3 speed chainring (with a chainring derailleur that works fine)

    Since the rear derailleur (indexed) moves inward or outward as much as the shiter tells it to do it, if i change it from 6 a speed shifter to 9 speed shifter, the rear derailleur should still work fine, right?

    Reply
    • Yes, correct. Shifter should be just fine. With a few notes:
      9 speed cassettes are more “tightly packed” than 6 speed ones – sprockets are closer together. The system will be more sensitive to any imperfections. So you might see a lower quality in shifting if either:
      – Cables and housing are worn, or not properly routed.
      – Rear derailleur hook, or hanger is not straight (they sometimes get bent from impacts).
      – Rear derailleur has a lot of play in the pivots (is worn).

      Also:
      6 speed cassettes usually have a range of 14-28, or 32 teeth. While 9 speed ones are usually 11 (or 12) to 32, or 34 teeth (for MTB).
      In case the rear deraileur is not a long cage one, you might end up with some slack chain when running small-small combination (smallest chainrings both at front and back). That’s not a big deal, especially since that gearing combination should be avoided anyway, because of the severe cross chaining in that combo (similar gearing ratio can be achieved by using the middle front chainring and mid-part of the cassette).

      Finally, just in case:
      6 speed cassettes are usually using a freewheel systems, while 9 speed ones require a wheel with a freehub – so wheel (or at least hub) change will be needed.

  8. this article gave me the courage to mix the following:
    SRAM X0 9s shifter
    Taiwan 11-46T 9s cog
    shimano deore 10s with clutch

    worked like a charm

    Reply

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