Originally Posted by
TimothyH
Many things which can be done on the road are simply easier and more convenient on rollers.
Keep in mind that we are talking about specific skill drills, such as riding at high cadence for an extended period. When was the last time anyone here spun 110 RPM for an hour on the road? It can be done but it is very convenient to hop on rollers for an hour of high cadence.
This is just an example.
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?