1
vote
3answers
261 views

Theoretical question about double drivetrain (both-sides drive)

If one were to take a single-speed flip-flop hub, and fit two identical freewheels, and couple them to two identical chainrings (i.e. two drive-side cranks, one on each side of the bike), you would ...
14
votes
2answers
2k views

Is there a practical gain from elliptical/oval chainrings?

I have seen competitive (amateur) cyclists with oval chainrings (front). What is the deal? Are they just for showing off, or is there a practical gain from it (different force transfer).