Scooterotica

Here is what I [think] I know about the P200e engine/transmission/wheel:

Circumference of tire 52" measured

Per published specifications:

Stated engine 12 hp @ 5700 rpm

Stated top speed 65 mph

Engine to clutch 23/65

First gear 12/57
Second gear 13/42
Third gear 17/38
Fourth gear 21/35

Published specs came from:

http://www.scooterhelp.com/scooters/VSX1T.p200.html

Have been trying without success to go from this known information to top mph in each gear. Except for measuring circumference of the tire I have excluded my calculations and - probably - mistakes.

So... How should I make these calculations? And is 5700rpm the engine redline or merely its point of highest horsepower?

Thanks!

You're close....... this link is from the same site, hope it helps:

http://www.scooterhelp.com/tuning/vespa.gear.calc.html

Thanks for the link!

It appears that my P200e is topping out about 4500 rpm.

Do you know for sure that it has a standard gearbox?
If a previous owner fitted a t5 4th gear it would lower your top speed.

SF

No, I don't know that the actual gears inside the case meet the published tooth counts. The scooter was running when I got it so no reason to split the case.

What are the possible combinations with the clutch output gear and the Christmas tree input gear? The P200e default appears to be 23/65. I've seen clutches on eBay with as few as 20 teeth on the cog, with 21 and 22 more common. Have not seen any with more than 23.

To maintain the 23/65 mesh seemingly would require 68, 67, and 66 teeth on the larger gear. Don't recall having seen any of those.

It might be too early in the morning but what is your issue? If your p200 is just not fast enough, then you came to the right place

This visual gear calculator is very handy for what you want to do.

http://gearingcalc.free.fr/