Question: Can 9-speed cassette be used with 10-speed chain/derailleur or vice versa

Good to hear. Looks like it will work so I only need one trainer-specific wheel. I don’t want to spend much on this set up since I hate riding the trainer.

Thanks.

The initial thread was based on the premise that you’re saving your rear tire with the separate wheel. If you hate riding the trainer (I certainly do) and you only train on it once in a while, I don’t think you’re going to wear out your rear tire that fast…so maybe just use your regular (training) wheel?

Alternatively, low end Shimano or SRAM 10s cassettes are around $60 new, or less slightly used. So maybe just convert the current 9s wheel to 10 that way and be all 10. If you’re Campy, perhaps a Veloce level or a Miche cassette?