[geeks] Electric bike?

[Francois Dion]

Anybody built their own electric bike or has one?

I'm working on my 3rd bike. I'm trying to make a lightweight unit this
time, and easily removable. The previous one was built on a mountain
bike but when you run out of battery... it is really heavy. Each SLA
AGM battery is 10lbs and I use 2. Then a few more pounds for the
motors and another lbs for the controlling circuit and wires. Mountain
bike itself, altough aluminium, is a 90s vintage XT gruppo
w/suspension fork so it's not light. Probably 60lbs total!

Beside the weight, another reason i'm wanting to go with a road bike
is the reduced friction, better aerodynamic position etc (i know it's
not anywhere near a recumbent but still).

I picked up a Kollmorgen flat servomotor which would fit perfectly in
the "V" above the bottom bracket but I haven't found a good way for
the transmission. For the mountain bike I put the two motors on a
friction drive knurled shaft from the defunct EV Warrior with a pivot
and I use an STI type shifter to tension the unit against the rear
tire (I replaced the knobby tires with some city slicks, obviously).

I was thinking that the right side crank could be replaced by a tandem
crank, but that means that you have to pedal at all time when the
motor is engaged (like a fixed gear bike). I dont want that.

I know of one way to resolve this:
http://www.cyclone-tw.com/newkits.htm

But that's not what I want either. Any toughts?

Ciao,
Francois