Re: Top Speed, 80cc Chinese motor? what is the record?
my race bike now has a modified ktm expansion chamber, mm ashtray head, 22mm mikuni and "backwards" engine (carb's in the front, exhaust out back.)
24" wheels and a 37t sprocket. and it weighs 53lbs.
i gps'd it at 46mph. it still revs out with that sprocket. i could easily pull a 28t and hit 50+, but it's geared for the relatively short straights at the gokart track and needs to be quick out of the turns. this season i'm gonna try out a 40t. sacrifice some top end to gain more torque outta the twists.
the key to top speeds is gearing. if you're designing a bike to do nothing but go ast fast as possible, you'll need to sacrifice low speed quickness. a low gear, a looong straightawsy, and just let it freight train along until you get there.
the trick is building a motor that won't run out of torque to pull such a low gear. putting a 30t on a stock china and you'll go nowhere, slowly.
i call bs on speeds over 40 with an untouched stock