Question. If I run an 11-42 1x on my MTB, can I use an 11-28 road cassette on my kickr without adjusting the derailleur? Or do I need to buy an 11-42 cassette? I just bought the kickr core, one of the reasons why I bought it is to do my TR workouts on my MTB, I want to be as specific as possible on my training.
You can run the 11-28 just fine. You may need a small barrel adjustment as the freehub body location can vary enough to cause skipping. But your other derailleur settings will be fine.
Sweet! Thank you.
… and potentially an adjustment of the limit screws as well, depending on how far off the cassette ends up from the axle face on the trainer compared with on the wheel.