Should I use a road bike or track bike on my rollers or trainer? I have a road bike with a triple, a track bike with a high gear ratio.  Which should I use on my trainer for use with training videos?  Should I use a geared bike, freewheel single speed or fixed gear?
The bike to use will depend on the reason for using the trainer. If your use of the trainer is for off season track training use the track bike, road racing  use the triple,etc. If you just want some saddle time, the triple will simulate all of them to an extent, you can select the gearing of the track bike,the fixie or the single and leave it there.