Originally Posted by
rubiksoval
Which you can do on a trainer, of course.
But a better question would be why you think you need to ride 110 rpm for an hour, ever?
Spinning 110 RPM for an hour is just a drill. I don't
need to do it but like any other drill it helps develop other useful skills and habits.
For example, riding at high cadence for an extended period has helped me spin faster on long steady 2% or 3% grades. I'm just able to turn my legs over faster, that's all.
Another example is riding a fixed gear bike with fast road riders. Keeping up with reasonably fast guys on $6k carbon Di2 bikes when I'm on a 48x15 or 48x16 fixed-gear requires some spinning. A paceline on a flat course can force bursts as high as 130 RPM and steady riding at 110.
Again, an hour at 110 RPM is just a drill, that's all. I do it early in the season and typically on a fixed gear bike. Rollers make drills like this very convenient. I'd imagine a trainer would as well but I don't have a trainer, just rollers.
-Tim-