My wife as a Trek Verve 2 with an 8-speed cassette. I have a Trek Domane SL5 with an 11-speed cassette. I bought a Wahoo Kickr Core as it's much less expensive than the Kickr. It doesn't come with a cassette, which was fine by me. I initially installed the 8-speed cassette incorrectly as the shim had to go on a certain way and I had it backwards and it caused the cassette to wobble. Reinstalling the shim properly fixed the problem.