BMC 1000W can motor info

I'm hoping someone here has one of these motors, http://www.thesuperkids.com/10wabmcbrbim.html and can help me out.

I'm trying to design a mid drive to assist climbing the steep hills around here, top speed not so important.

This is what I have so far:



With the motor & planetary driving a 48 tooth chainring the motor RPM seems low at the cruising peddling RPM of 60-85RPM (= motor RPM ~730 to ~1030).

There is no Kv value for this motor that I can find on the BMC website (what a mess!) and the seller doesn't know either.

Does anyone know if this range of motor RPM will be too low to be anywhere near efficient?

My initial thoughts are that another gearing factor of 2 to 2.5 is required. Which would make the chainring too large and/or the motor cog too small. So most likely it will require a jackshaft.

PS: hello all (first post)!

I have one and have abused it for a year now. Unfortunately I have no tachometer.

My top speed @ 60v is 28mph (26"wheel") usually about 26.5mph at 58v.

First stage is a 4.8-1 planetary. Second is 18t pinion 60t ring for a 3.33-1 reduction.

Also look into beefed up gearbox from Scott at www.evdeals.com its pricey but well with the security of not being afraid of destroying another clutch bearing.....

Excellent. Thanks for the reply and the link to the stronger gearbox.