I've only participated in spinning classes at the local YMCA for the last few years. Initially, we had instances where the RPM's would hit 150-160. Maybe we were doing the Les Mills stuff. I don't know. It didn't take too long for me to figure out that pace wasn't too smart for me. Eventually, that fad or whatever went away. Currently, most rides top off at 110. For what it's worth, I credit spin class with helping me turn a corner in cycling. The use of intervals and such have really helped me in the off-season (Mid-West winters), along with some gym work on the core and flexibility.. I rarely attend spin classes when the weather is suitable for real cycling. This past year, I actually have felt stronger in March, than in September. Probably as a result of just riding and not spending as much time on the previously mentioned stuff. And yes, most of the class members and instructors are not cyclists. We hit a rainy spell in August, so I joined in my first class since April. The instructor asked me where I had been. I looked at here with a little humorous contempt and simple responded with, "Outside?"