[Aresab]

Universal Cycles has them I believe: Shimano FC-M8100-1 XT Crank Arms - 12 Speed
They are very reliable and have been in business for a long time..

 

[Aresab]

Thanks so much for the tip!!! Ordered!!!

My pleasure. BTW, on my non-boost KHS 7200 I'm running Shimano MT900 cranks which are the "black cranks" used as a stop gap until the XTRs were ready and they are basically the XTm8100 with different graphics. They work fine on the bike and are over out a bit due to 52mm chainline however the newer Shimano chains seem to have more ability to flex than 10 speed versions (never used 11-speed Shimano chains) so they cope. I get zero back pedal issues on this bike as well.

 

[Aresab]

Which cassette and chain are you using?

On the KHS, Sunrace MZ903 11/51 and M7100 chain. On my Breezer, SLX M7100 10/51 XT M8100 chain. Both bikes have XT M8100 shifters and the MT900 cranks, both 142mm rear.