Originally Posted by nubikeshop
Hey all. A build of mine has a 68.5cc with a 44 tooth rear chain ring. Gets above 30 easily, max of 39 downhill. I was curious if it would be safe to upgrade to a 36 or lower tooth chain ring. It would be cool to get some extra speed out of this thing, but would I be seriously compromising safety, structural integrity, ability to start easily, etc...?
I would say it all depends on how safe you think your bicycle is at 40 m.p.h. Most of these bikes weren't made for that for any extended period of time.
Myself, I only use the best components and some very good tires, and still don't care to go 40.m.p.h.
That is strictly my opinion!