Say you’re upgrading on a budget and can replace a few parts at a time and still have a perfectly functional set of 9-speed derailleurs. Can you use them with 10-speed shifters and gearing? We got this question from a reader, so we turned it over to the heavy hitters in the mountain bike drivetrain category, SRAM and Shimano. Here’s what they had to say regarding mountain bike drivetrains:

MORGAN @ SRAM: For the rear, no. The cable pull is different for the 10-speed rear derailleurs and the 9-speed rear derailleurs won’t line up properly with the cogs when used with a 10-speed shifter and cassette. A 9-speed front derailleur will work, but it’s not optimized and may result in more chain drops or slower shifting -or no shifting at the extreme ends of the cassette- because the gap between plates is larger than what’s required for a 10-speed chain. The cage is also shorter if you’re viewing it from the side because it doesn’t have to work with as large of a chainring as what’s typically found on a triple.

JOE @ SHIMANO: Not really. Anything with Mega9 on it was designed to work together as a 9-speed system, and anything with DynaSys on it is 10-speed only. The cable pull ratio is different. The 10-speed stuff pulls a lot more cable, and the lever arm on the rear derailleur is much longer. We designed it this way so when you do your shifts from the smallest cog all the way up, the lever feel is the same all the way through the range. Also, the 9-speed was more of a universal system, too, but the DynaSys is an exclusive mountain bike system.

Got a burning question? Email us and we’ll do our best to get an answer straight from the source!


  1. You CAN however, use SRAM 9 speed derailleurs with Dynasys shifters. The pull ratio is the same strangely enough. Been doing it for a while no problems to speak of.

  2. Do 10-speed cranks still work with 9 speed systems? If I need to upgrade JUST my crank set, do I need 9-speed specific cranks, or will the new 10 speed shimano cranks work just as well? … Them crank rings are a lot like ink cartridges on inkjet printers. Replace the rings once or twice, and you’ve practically paid for a whole new crank set…

    • HI there Christophercules, are you saying that if I currently use a 9×3 ultegra group, I can switch to a “10 speed” crankset on the front and it will still work?

  3. The difference between a 9 speed and a 10 speed is chain width. To fit a 10 speed where your 9 speed cassette means that the chain is smaller. Running 10 speed crank with a 9 speed is no problem. The other way around will have you with an angle grinder for hours.

  4. @Kovas

    Generally speaking, you could do that. Please remember, however, that new cranksets from Shimano (5700, 5700, 7900 and most probably 4600, too) have a little bigger spacing between chainrings than kit was the case in previous generations. It is not a dramatic difference, but it may slightly affect shifting quality. It also means that you should consider replacing your FD as well.

    Other than that, 10-sp cranksets do work with 9-sp drivetrains, but again – shifting quality might be slightly inferior to dedicated 9-sp ones.


  5. You can use the following drop-bar set-up

    Shimano 10 speed cassette
    Shimano 9 speed mountain bike rear mech
    Shimano 10 speed sti’s

    This was the set-up of choice for the Three Peaks cyclo-cross, giving a 1:1 bottom gear ratio for the tough bits!

    (also useful for fully laden touring)

  6. If you have Shimano Mega 9 why would you want to switch to Shimano DynaSys 10? Oddly enough the nine cog system has a wider gear range then the newer ten speed system because Shimano had to compromise and drop the 44 tooth large chain ring to a smaller 42 tooth gear system in order to give the rear derailleur enough chain take up to shift to the larger 36 tooth rear cog.

    So really Shimano’s new DynaSys 10 is a compromise system that is trying to accommodate both the 26er and the 29er crowd. The 26er crowd lost top end speed with the loss of the big 44 tooth chain ring and while with the larger 36 tooth cog the 29er crowd gained a little but it is still not a low enough gear ratio to replicate the low gearing of 24/34 geared 26er.

    I think the only winners with Shimano’s DynaSys 10 are riders that run a twin chain ring set up who never break 40 kph. But really, who wants a mountain bike that can’t break 40 kph going down a hill? Going fast down the hills is one of the greatest pleasures of mountain biking and Shimano killed it!

  7. I’m running an X0 crank with a 9 speed setup (11-34 XT cassette, x0 rear shifter, x9 RD, 2 speed x9 front shifter, and LX derailleur).

    Works OK. Adjusting the front mech is a bit tricky.

  8. @alloycowboy

    you do get 42T instead of 44T in the crankset, but you also get 36T instead of 34T in the cassette. 42/36 gives actually gives you a lower ratio than 44/34. Moreover, the differences in ratios between gears are smaller which is perfect if you care about cadence. So IMHO it does make sense.

  9. @ mkrs

    I think he was talking about 40/11 (or 42/11 at the highest) vs 44/11 …. not much point going 42/36 when there are much better gearing combinations available… allowcowboy was talking about top end speed. If he was talking about the lowest gearing then we’d be comparing something like 26/36 (or 24/36 at the lowest) and 22/34.

    not taking one side over the other… just stating the facts.

  10. @DasBike – 9-speed and 10-speed chains (Shimano/SRAM, not sure about Campy) both have the same width between the inner plates, thus chainring thickness can be the same for both 9&10-speed. Plate thickness is where the 10-speed chains become a bit thinner.

  11. This is article was perfectly timed. I thought I could upgrade my 1×9 (Mega 9) setup to a 1×10 Dyna Sys. I thought I could just install 10 speed shifters and that would be enough. I figured out real quick that it doesn’t work. I ordered a new rear DS derailleur today. Thanks for the confirmation.

  12. going from a 44 to a 42 chainring you only lose 4 gear inches.

    I personally like dyna-sys. The 11-36 cogset gives me enough range to run a single 36 or 38 ring and still make it home in one piece. By the way, the Shadow Plus XTR derailleur is probably the best mechanical derailleur to come out of any of the three companies in a long time.

    Also honestly, nothing is stopping you from swapping the 42 to a 44 if you really need that extra gear or you can spin your legs a bit faster

  13. Ryan – 10/19/11 – 10:46am

    You CAN however, use SRAM 9 speed derailleurs with Dynasys shifters. The pull ratio is the same strangely enough. Been doing it for a while no problems to speak of.


    Hold the phone? Really, this works? Awesome if true!

  14. dynasys shifter + sram 9v rd = ok
    sram 9v shifter + dynasys rd = ok
    yes,it really works…you can mix shimano x sram and use the best of both worlds…

  15. @KT, agreed on all your points except installing a 44 tooth chain ring only because I question the front derailleurs capacity to make the shift all the way from the 24 small all the way up to the 44 big chain ring. I am just not sure if the capacity is there in the derailleur with it out being tempermental.

  16. Here’s a question: are there any cassettes that don’t gouge the F out of my freehub bodies? XX cassette I imagine is one, since i hear it drives off the big 36T cog, considering it’s usually the smallest 3-4 that gouge.

  17. So if I have a SRAM X0 9spd RD, I can upgrade to 10 spd by simply getting a dynasys rear shifter, 10 spd cassette, and 10 spd chain?

  18. Can i use sram x7 shifter (9 speed) with zee or saint rear derailure (both 10 speed). Will be using 9 speed cog. Since the latest zee and saint derailires are said to be 1:1 ratio and the x7 shifter is a 1:1 shifter….will it match.?

    I habe the said 9 speed mechs. Im planning to buy the zee or saint drlrs only due to its” switch” for less chain “bounce”

    Would appreciate a feedback.

    Thanks guys

  19. @ Rommel Timonera,

    I know it’s a little bit of grave digging…but,

    This was discussed on various forums including PB which I was in.. Long story short, YES
    a 9-Speed X-Series (x5+) or X.0, will work with a Zee 10spd Derailer. There’s a video on Youtube too showing it works fine and appears to shift very decently. It was recommended that a 6mm Spacer be put between on the attaching hanger screw (to space out further)to really fine tune it but seems to work good regardless.

    Also, I haven’t seen anyone try it with the M820 Derailer, but gonna be getting one soon and will try it out to a X9 Shifter.

  20. All professional,

    Any one have try to use sram x9 rear derailleur (9 speeds) with sram x7 10 shifter + 10 speeds cassette? Can this work well? Currently I using sram x9 (9 speeds derailleur) want to upgrade to 3×10 speeds, so planning to just buy a sets of sram x7 shifter (3×10 speeds) and 10 speeds cassette, please comment and let me have your advise, can this work?

  21. All I can say is Shimano made it impossible to run 10 speed mountain mech with 10 speed road STI levers by changing cable pull rates (which they didn’t need to do). Cross platform compatibility was always Shimano’s strong suit. Then they messed with it for no good reason. Now it’s a science project. We expect that from Campy.

  22. Hi guys, I have it on my bike and I can tell you it is working flawlessly:

    Any SRAM 9 speed shifter will work with Shimano 10 speed rear derraileur + 9 speed cogs !

    Depending on chainstay lenght and cable arrangement some shins might be necessary.

    I have it with X0 gripshifters + SLX RD+ derraileur + HG61 12-36T cogs for the ultimate ratio.

    I recommend any clutch 10 speed rear derraileur from SHIMANO.

    Just to reassure you, we have put it the other way around too:
    X0 9 speed derraileur + Shimano 10speed shifters on 10 speed cogs, guesss what, it works, too !

    Try it, it is worth it !

  23. Can i use sram x5 9 spd trigger shifters with shimano ultregra ss 9 spd rear derailleur? The bike i am working on is 2001 giant tcr one which i am looking to do a simple conversion to a flatbar. Any trigger shifter info and recommendations would be appreciated! Cheers

What do you think?