where can I get 15hp capable 2speed transmission

[kerosene]

This is quite off topic - but its sort of for a bike concept (in my head).

I am playing with a concept of a supreme range aerodynamic electric motorbike. Electric bikes work ok without transmission but the currents go up and efficiency down on low speed starts and accelerating - or top speed has to be compromised. A simple 2 speed transmission with 1:2 and 1:1 ratios would be ideal remedy for the issue.

As this forum has people of various backgrounds I was wondering if someone would know from what kind of machine one could nick such a transmission.

Planetary 2 speed would be ideal - at cruising the transmission would be efficient 1:1 straight through.

thanks.

[Pigeon]

It's not an "issue", it's a problem.

You might find something on a ride-on lawnmower.

Probably easier though to get a scrap "normal" motorbike - with a buggered engine or something - 125cc or thereabouts - two-stroke, and use an angle grinder to cut the crankcase part off the gearbox to give you just a gearbox on its own. Could always mess with the detents to reduce the number of available ratios.

Do you really mean 15hp? That's about 10kW and a battery capable of supplying 10kW for any reasonable amount of time is going to be large, heavy, expensive and hard to find.

[blod]

Elecrtic bike eh?

[dan19evans]

blod said:

Elecrtic bike eh?

[Gibby78]

would you not be better with something like a CVT gearbox from a moped or a Variator system again from a ped, both have centrifugal clutches and you can change the rollers on a variator system to suit, crashed Peds are ten a penny and weight shouldn't be too bad