Hawkwind,
Do you know if these guys are using any type of speed controller? I've been working on a "RPV", or Remote Piloted Vehical. It uses 2 wheel chair motors running 24 volts. Problem is the Pulse width modulator speed controllers can't handle the amperage for any length of time. I took them out of these Chinese electric skooters that are "currently" (Sorry... Pun intended.) flooding the market over here, and they only last a few minutes at best.
Thanks!
Smitty