In thinking, that an 11 spd Shimano rear mech will work fine with a 10spd shifter, cassette and chain?
I’m thinking about a weekly upgrading to 11spd, and also have a rolling chassis needing a 10spd rear mech and chain to finish- Im thinking to donate my current set up to the bitsa while my bike gets modernised

Nope cable pull different from 10-11 speed 🙁

Hmmm.. Next plan, how do I sneak a purchase of 11spd mech, shifter, cassette and chain past SWMBO

M8000 rear mech worked perfectly for me on 10 speed SLX cassette and 40t T-Rex. Better than a Zee for me.

We’re all in the same boat, it would seem…

Current SLX 11spd rear mech works great with 10spd shifter (older SLX) and 10spd cassette (first SLX 11-36, now SunRace 11-42).

Well, I’m on SLX shifters and a sunrace 11-42 10spd… I might have to try out the M80000, and put it in the draw until I get the rest of the drive train if it doesn’t do the business

So long as your shifter matches your cassette (ie both 11 or both 10 speed) then i think the rear mech will be fine as the mech isn’t doing any of the indexing.

This isn’t based on any definitive knowledge other than thinking it through a bit so I’m happy to be corrected but I’d certainly give it a go before buying anything new..

Yep, I get your logic, and if the mech does not work, then your next purchase of an 11spd shifter will get you up and running until you get the cassette and chain for the full upgrade

I’m running a 11 speed SLX rear mech with 10 speed XT shifter and cassette with 42t expander cog and it shifts perfectly. Shimano and others will tell you it won’t work but it definitely does.

So long as your shifter matches your cassette (ie both 11 or both 10 speed) then i think the rear mech will be fine as the mech isn’t doing any of the indexing.

Agreed. My understanding and experience is its the actuation of the shifter that counts. !0 speed shifter with ten speed cassette. Rear mech is (largely) irrelevant.

My understanding and experience is its the actuation of the shifter that counts. !0 speed shifter with ten speed cassette. Rear mech is (largely) irrelevant.

Except that isn’t correct. It may work in some cases but the actuation of the mech is not irrelevant.

I’m using an xt m8000 mech to shift a shimano chain across a sunrace 11-42 10 SPD cassette. It works like it was designed to.

jobro – Member

Agreed. My understanding and experience is its the actuation of the shifter that counts. !0 speed shifter with ten speed cassette. Rear mech is (largely) irrelevant.

Nope, not right, the cable pull has to match between the shifter and mech. Mech doesn’t care how many speeds you have, but it does care how much cable you shift.

I thought you were talking road :/

Ignore me it may work fine 🙂

Yeah, I can reliably report back that an SLX 11 speed rear mech works well with a 10sp SLX shifter and sunrace 11-42 10spd cassette