212cc top speed?

[cloakedvillain]

I don't want to put you down but I think you should gear it to top out at 50mph at 3600 rpm. It is not worth removing the governor because an industrial engine is at peak power very close to under to the limit. Same for rev limiters in oem vehicles, its set a little higher than peak power with the stock tune and parts.

A grom has around 8 hp and peaks in the mid fifties.

8hp cannot do that. Aerodynamic losses are way too high. Sport bikes need over 20 hp to get to 80mph and I shouldn't need to show a picture of sport bike to show why a cruiser cant do that without another 15 hp on top of that 20hp.



Their bike cannot get up to the hypothetical max because it just cant punch through the air hard enough. Higher speeds are exponentially more difficult not linearly. 3 hp can get high 30s with no aero, it takes a little over 30hp to get to the high 70s with no aero.

The Honda cbr300r and the crf300l have the same exact engines but the sport bike can go a good 20 mph faster because it isn't fighting the air.

 

[Sidewinder Jerry]

8hp cannot do that. Aerodynamic losses are way too high. Sport bikes need over 20 hp to get to 80mph and I shouldn't need to show a picture of sport bike to show why a cruiser cant do that without another 15 hp on top of that 20hp.



Their bike cannot get up to the hypothetical max because it just cant punch through the air hard enough. Higher speeds are exponentially more difficult not linearly. 3 hp can get high 30s with no aero, it takes a little over 30hp to get to the high 70s with no aero.

The Honda cbr300r and the crf300l have the same exact engines but the sport bike can go a good 20 mph faster because it isn't fighting the air.

Which is what I'm saying. Around 45 mph is a more realistic expectation and can be done using 3600 rpm on 26" tires. Meaning run a 10\60 or install a jackshaft and run {10\20 | 16\48}.

 

[BruceBanner1983]

I don't want to put you down but I think you should gear it to top out at 50mph at 3600 rpm. It is not worth removing the governor because an industrial engine is at peak power very close to under to the limit. Same for rev limiters in oem vehicles, its set a little higher than peak power with the stock tune and parts.

A grom has around 8 hp and peaks in the mid fifties.

8hp cannot do that. Aerodynamic losses are way too high. Sport bikes need over 20 hp to get to 80mph and I shouldn't need to show a picture of sport bike to show why a cruiser cant do that without another 15 hp on top of that 20hp.



Their bike cannot get up to the hypothetical max because it just cant punch through the air hard enough. Higher speeds are exponentially more difficult not linearly. 3 hp can get high 30s with no aero, it takes a little over 30hp to get to the high 70s with no aero.

The Honda cbr300r and the crf300l have the same exact engines but the sport bike can go a good 20 mph faster because it isn't fighting the air.

The biggest size sprocket available with the moped hub I got was 48t, but if I knew how to gear it to top out at 50 with the governor, that would be just fine if I could get the correct size rear sprocket. If anyone knows what size rear sprocket I would need with a torque converter and 10t sprocket on the jack shaft for a 26” wheel to top out at 50-55, I’ll see if I can find it.

 

[Sidewinder Jerry]

(RPM × Wheel Diameter × π)÷(1056 × MPH)=Total Reduction.

You'd have to run something like this:
CVT 10 >JS[20 | 18] >to rear 48. This'll give you a speed around 52 mph.

If you could get a 20t sprocket and a 19t sprocket for the jackshaft it'll put you exactly where you want to be speed wise 55 mph.

David Staton could make you these sprockets.

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