My wife just got her new road bike so she can come with me sometimes. She really likes it so far. It has a 2x10 speed Tiagra groupset (11-32 on the back). I have a 2x11 speed ultegra, 11-30 on the back. From October I will do indoor trainings again and I am thinking about what would be the best way so she can also use my smart trainer (it has 11-30 cassette).
Should we buy another trainer, or is it possible (or cheaper) to convert her bike to a 11 speed one so we could easily just swap the bikes? (I am considering to buy a new wheelset for me, can she use mine then?)