Originally Posted by
BlazingPedals
That 70T would be a little high for a lowracer with a 20" drive wheel but not outrageous. Good for someone who doesn't like spinning, or maybe just doesn't like using an 11T cog in back.
The OP has never made any sort of indication that this is about a recumbent, just that he's going to do 50mph on flat ground. Even if it does turn out to be something not diamond-framed, we're looking at a sustained effort of ~120rpm @ 1,300-1,400W. Unless it's fully faired, in which case who cares. Fully faired can go
really fast without a pie-plate in the front.