Sprocket Selection.

I currently have a 36t sprocket on my "80"cc ebay kit (700c wheels). I've got it running great, where it maintains 29-31mph on the flats and has hit 38 on a little hill. Whenever it starts to get around 34mph and higher the vibrations which used to occur at 27mph, reoccur.

I just ordered an expansion chamber exhaust from SBP, and anticipate at least a couple mph more up top. Additionally, I plan on getting the slant head if they ever come back in stock at zoombicycles.

I am going to buy Creative Engineering's clamshell sprocket adapter and am torn between choosing a 32t and 34t sprocket.

Anyone care to chime in with some experience?

i have a 48cc dualstart with a 44t sprocket on my 26" mountain bike
im reaching 32mph on the flats.

I contacted Manic Mechanic for a recomendation on the sprocket for my bike and they recommeneded a 52 tooth. But a lot depends on the terrain and the weight of the rider, I'm pretty heavy and need to climb some fairly big hills. I would ask the company for a recommendation.

Why do you want to go over 34 m.p.h. on a bicycle? Hardly anything on the average bicycle is designed to go that fast. I hope you are running the really high dollar tires, because most of these cheap Chinese tires arn't rated for near that fast for prolonged use.
Wear a dmn good helmet.

John

Its not that I want to go 34 mph, its that I want to do 30 at a comfortable rpm. I hate having to beat on the motor to get around at that speed.

And sometimes its nice to gun it on one of floridas wonderfully flat and smooth roads. I ride with a Full face DOT helmet when I go far, and a Giro Atmos (Many professional riders who exceed 40mph use them) from my road bike on shorter trips.

I hate how you can never post something in these forums without someone chiming in with this common gripe. Cheers.

FWIW I went with a 32t sprocket to keep RPMs down.