11 and 12s compatibility on XTR 9100 Drivetrain?

[tuscanyswe]

So looking at some components and a new jungle for me who is usually a road junky so this mtb stuff is uncharted territory

Thinking of getting xtr m9100 brakes and shifters + the rear derailleur.
I have understood that the 9100 series is both 11 n 12s compatible but perhaps not the same as older 11speed?

My question is really this:

Will a 9100 series shifter paired with a 9100 series rear derailleur shift an m8000 (older xt) 11 speed cassette properly on a chris king r45 disc hub?
Or will i need a newer kind of 11 speed cassette (i read something about wide body 11s cassette)? If i cant use the older cassette will my CK rear hub/body accept the new 12s kind cassette? Guess not right?

Thanks
B

[EB]

FWIW a big selling point with XTR 9100 is the ability to shift smoothly up and down under high load. This seems to require the new XTR cassettes.

[tuscanyswe]

Thx but right now just focusing on weather they are compatible or not. If I can potentially get even better shifting with the new 12s cassette that is ofc good but i cant fit micro spline body on my wheels currently anyways.

[John H.]

My understanding is that you still need a cassette for 11 speed.
The 11 speed has stem spacing as 12- But only has 11 cogs. Also, I don't think they ever actually sold that cassette.

You also need the Micro Spline free hub body for the 9100 cassette- Compatible XTR chain and some sort of compatible chainring too.

When I 1st put my XTR on- I used it with a SRAM Eagle cassette, chain and chainring and it worked out ok.
Shifting was even better once I moved to XTR cassette, chain and 12 speed XTR wolf tooth ring.

[tuscanyswe]

Originally Posted by John H.

My understanding is that you still need a cassette for 11 speed.
The 11 speed has stem spacing as 12- But only has 11 cogs. Also, I don't think they ever actually sold that cassette.

You also need the Micro Spline free hub body for the 9100 cassette- Compatible XTR chain and some sort of compatible chainring too.

When I 1st put my XTR on- I used it with a SRAM Eagle cassette, chain and chainring and it worked out ok.
Shifting was even better once I moved to XTR cassette, chain and 12 speed XTR wolf tooth ring.

Yes this is what the litterature tell us at first glance. But i have heard different from various ppl n romours. I would like to debunk or proceed with this theory

Have you tried new xtr 12 shifter in 11s mode with xtr 12s rear der and regular (old) 11s cassette?

Or even an old 11s shifter with the new xtr 12s rear der and regular (old) 11s cassette?

[yinzerniner]

Originally Posted by tuscanyswe

Yes this is what the litterature tell us at first glance. But i have heard different from various ppl n romours. I would like to debunk or proceed with this theory

Have you tried new xtr 12 shifter in 11s mode with xtr 12s rear der and regular (old) 11s cassette?

Or even an old 11s shifter with the new xtr 12s rear der and regular (old) 11s cassette?

Cassette spacing for regular 11s shimano MTB is wider than the micro spline 11s, so it won’t work.

What might work is a 12s SRAM XD cassette. Others have reported that it’s ok with shimano xtr9100, and the shift feel and derailleur benefits are mostly there.
https://singletrackworld.com/forum/t...compatibility/

Also new xtr shifter with old xtr derailleur and 11s cassette seems to work fine as well
https://youtu.be/C1AQfvgZ1DM

[tuscanyswe]

Originally Posted by yinzerniner

Cassette spacing for regular 11s shimano MTB is wider than the micro spline 11s, so it won’t work.

What might work is a 12s SRAM XD cassette. Others have reported that it’s ok with shimano xtr9100, and the shift feel and derailleur benefits are mostly there.
https://singletrackworld.com/forum/t...compatibility/

Also new xtr shifter with old xtr derailleur and 11s cassette seems to work fine as well
https://youtu.be/C1AQfvgZ1DM

Thanks

I also know of 2 who claim that old s11shifter will work with new rear der for 11 older 11s cassette.

But if one can do both new shifter with older rear der and old shifter with new rear der than one cant help to wonder why new shifter should not work with the new rear der with older 11s cassette.

[yinzerniner]

Originally Posted by tuscanyswe

Thanks

I also know of 2 who claim that old s11shifter will work with new rear der for 11 older 11s cassette.

But if one can do both new shifter with older rear der and old shifter with new rear der than one cant help to wonder why new shifter should not work with the new rear der with older 11s cassette.

Its not guaranteed to work because the cable pulls can be the same but how the rd is designed will determine the position. So a 3mm cable travel distance might move one rd 4mm on the cassette and another 3mm on the cassette. But if someone has documented evidence of the above then by all means try it out. Sometimes you have to bite the bullet instead of relying on others to do the grunt work. Or just see if there’s a friendly LBS that will allow you to put your wheel on a bike with the new groupset already on to check if it works.

[tuscanyswe]

Originally Posted by yinzerniner

It won’t work because the cable pulls can be the same but how the rd is designed will determine the position. So a 3mm cable travel distance might move one rd 4mm on the cassette and another 3mm on the cassette.

But i haven’t seen any evidence of the exact situation you’re speaking of, using the new shifter and rd on an old cassette. Sometimes you have to bite the bullet instead of relying on others to do the grunt work. Or just see if there’s a friendly LBS that will allow you to put your wheel on a bike with the new groupset already on to check if it works.

Sure but since im a roadie i assumed perhaps wrongly that this would be tested by those on mtb drivetrains by now. At least more than seems to be the case.

Its all very weird to me considering i cant understand for the life of me why shimano would launch a 12 speed group with an 11s option for the shifter that is not back compatible with their older 11s stuff. When the new 12 speed and 11s cassette (that they are no longer selling) requires a new body or wheels even.

Considering every rider who then has the option to run the new 11s setup can than just as well run the 12s setup as they have all the parts required and cant use old wheels even. What was the idea here? It does not make any sense if this was the case (to me at least).

[John H.]

You should just get the 12 speed upgrade and be done with it. In the grand scheme of bike parts it is not expensive.
Rear derailleur, shifter, cassette, chain, chainring and freebody-
Don't need brakes or cranks.

[tuscanyswe]

Originally Posted by John H.

You should just get the 12 speed upgrade and be done with it. In the grand scheme of bike parts it is not expensive.
Rear derailleur, shifter, cassette, chain, chainring and freebody-
Don't need brakes or cranks.

Well I dont need or even want 12 speed so not a good option for me. 1 x 11 is more than enough for this bike. adding a 50t cog does nothing but ad weight for me unfortunately.

I just think the xtr9100 series is a tad prettier than the 9000 series esp the rear der + its goes better with titanium (imo). And i have chris king wheels so no body is available afaik even if i wanted to go that route.