My gym you call up that day - after 12 noon for the after work classes. If I had to be there 30 min prior to get a bike, I'd never go to spin. I think that is what my work gym spin classes are like, though the time is 15 min prior. But that isn't so bad since I'm just a building away. But I don't much like those classes and prefer my main gym's ones, so I call during lunch and reserve a bike.