Kickr compatibility issue

I have had a sram 11 speed bike on my kickr core. The cassette on the kickr is SRAM .
I just bought a trek checkpoint with 11 speed ultegra. I put the bike on the trainer (after putting in thru axle spacers) and I have a horrible grinding sound.
Is this to be expected with mixing shimano and sram?

You can mix and match between these brands as long as you match speeds (11 in this case).

First, make sure that you have the proper 142mm axle adapters setup (not the 148mm ones).

Second, have you tried using the barrel adjusting for the derailleur to fine tune the alignment?

1 Like

Actually this one is due to the relative position of the cassette on the kickr compared to the wheel (in or outboard by a mm or so) Ideally you adjust the limit screws to line up the derailleur under the smallest sprocket.

The problem with this is if that’s your only bike you’ll need to adjust it everytime to switch between road and trainer. The alternative (lazy option) i employ is find a sprocket which is quiet/smooth enough and leave it there.

Edit: on reflection as Chad mentioned, a small tweak of the barrel adjuster might be enough

3 Likes

A wheel-off trainer is like another wheel for your bike. If you have a caliper gauge, you can compare the distance from the axle face to the first cog between the bike wheel and the trainer. This distance has to be identical (down to something like 0.2mm) to allow no-adjust transition from the trainer to the road. Shimano 11-speed cogs are spaced 3.74mm apart, so you can see that even a difference as small as 0.5mm is more than 10% of the cog-to-cog distance. In theory you can adjust the trainer’s cassette position with spacers, but the degree of precision needed would require 0.2mm spacers, which I’ve never seen.

Otherwise, it’s barrel adjuster time. The simplest thing to do is to leave the limit screws alone and stay away from the two ends of the cassette.

2 Likes

yep never thought of the spacer, even better idea. It would effectively do the same job as adjusting the limit screw…

hey sthose typos were deliberat

1 Like

I have no idea if these are the right inside diameter, but I wonder if centerlock disc rotor shims (0.25mm thich) would be useful for adjusting cassette location on the freehub?

1 Like

I assume you mean the barrel adjuster rather than the limit screw(s). The former adjusts the alignment between shifter-defined RD stops and the cogs, the latter only set the travel limits of the RD.

i don’t really want to get into the weeds because I think your spacer proposal makes sense and it would depend just how badly out of alignment the shifting was, indeed tweaking the cable tension could be enough.

However, to answer your question nope I meant the limit screws as I had the impression the set up was significantly misaligned such that you would need to reset the derailleur under the 11/12 and then adjust from there.

I think that is exactly what your suggestion of the spacer would do but instead of re-positioning the derailleur you are re-positioning the cassette - much more practical. In fact so much so I’m going to try it on my kickr this weekend LOL

1 Like

If going the spacer route, keep in mind you may find your road wheel has the cassette further inboard than the trainer - and in that case, assuming you dont have spacers to take out on the trainer, you may end up adding spacers to the road wheel rather than the trainer. As long as you get that axle face to first cog distance equal between the road wheel and the trainer, you’re good to go. You do one good adjust of cable tension/barrel adjust + limit screws, and you can move back-and-forth without re-adjusting.

Again, this is the same deal as if you had training + race wheels to swap and you didn’t want to re-adjust the RD every time.

1 Like