Hi Mike, I have the newest Kickr trainer (axis feet, etc). For now the bike shop swapped the stock cassette out so that I can use my mountain bike (which is 8-speed if I understood correctly), but they can switch it back to the 11-speed cassette after I get a new bike.
When I’m searching for used bikes I just don’t know what to look for, as far as what speed bike (21-speed, etc) translates to a 10 or 11 cog. Enzo in an earlier reply said he regrets getting 2x9 and not a 2x11 shimano, and I just don’t know what that means 