Jockeys were well worn on one of our 11 speed mechs.  That’s fine I think, I’ve got some jockey wheels somewhere.  Tacx, grey, bearings.  Look fine.  Seem to be the same size, same number of teeth.

(then sinks down hell hole of replacing mech cable on a Canyon with internal routing and loses an hour of my life).

New (now continuous) outer on the cable.  New cable. New chain.  New jockey wheels.

Will not shift properly at all.

I ended scavenging part used jockey wheels off another mech.  Can’t work out what was wrong with the Tacx jockeys – they probably dated from 8 or 9 speed  – would they just have been too wide for the chain?

The 11 speed XT ones a re a bit funky in their design, the only ones that work in my experience are proper 11 speed XT ones. Not worth cost cutting IMHO

My XT jw only survived 9 months – the design is terrible. I would suggest Hope replacement, despite the price.

Another Shitmano failure with “current” XT – more medieval than current IMO.

I think they were just these – https://tacx.com/product/shimano-11-teeth-stainless-steel/

Claim they work with Shimano and I can’t see what else I’d have messed up in cleaning up the mech and fitting them but they just would not work.

They are for 9/10 speed

I put uberbike ones in my m8000 mech. Work fine.