Kickr core compatibility with xdr/force axs trek boone

Very excited to have taken delivery of my brand new kickr core but already having problems…

My bike, a trek boone 2020, uses sram force axs. So i fitted the kickr xdr driver and supplied axle spacer.

However, when in the smallest cog, the chain rubs the inside of the frame and the mech hanger. The axle also protrudes out the end of the frame, suggesting that the spacing of the whole kickr setup is shorter/narrower than my wheel. Not good! I’ve contacted Wahoo so will update this thread when they reply to me.

I’ve found the only solution to be loosening off the drive side axle spacer around 1-2 turns, effectively making the kickr axle spacing longer/wider.

If theres no clearer solution then I may just have a new, longer axle spacer made.

Anyone else run in to a problem like this?

I have a 2018 Kickr with the AXS driver. At least for the Kickr… there is a small silver cap that goes over the end of the axle. Same one that is used on the Shimano driver. Make sure that’s in place, or you’ll be 140/41 instead of 142

Thanks for your reply.

Do you have a picture, I’m not sure what you mean?

The only silver cap I’ve used is the threaded spacer (that came with the xdr feehub) that screws on to the axle on the drive side. This is slightly longer that the one that is used with the shimano 11speed freehub but it seems like it could do with being another 1 or 2mm longer

Just to clarify. I’ve fitted the freehub body and lock nut, but not the spacer


I think that @andymills is referring to the spacers that come with the Kickr Core.
see here:

You’ll want to use the right two adapters to get the spacing correct. The small one goes drive side, the larger goes non-drive with the appropriate side sticking out for your axle spacing.

Yup. I was specifically talking about the one to the far right.

Thanks guys, I’ve done all of that.

Further reading suggests that the drive side spacer is actually shorter than the standard 11spd one, i must have gotten them the wrong way round.

This makes it even more baffling as I still believe I need a spacer that is actually slightly longer than the 11spd one and substantially longer than the xdr one.

Anyway, thanks to erg mode, i can probably manage without the smallest cog and if it really bothers me I can ask some friends with a lathe to fabricate a suitable sized replacement