http://evmc2.wordpress.com/2010/08/10/hammarhead-volta-and-bigass-zev-hub-motors/
I moved away from the hub motor idea because of the unsprung weight, and everything was just fine... just another crackpot scheme - until I saw this on CraigsList for $40 - a '71 R5 frame.
Nuthin' but trouble.
This is my basic concept- totally stripped, totally naked, not at all street legal vintage cafe/roadracer:

(tank/seat art from http://www.silencetv.com/.
The first phase is to use the parts I have- a Mars ME0709/AXE 7245 @72V, but I want to design it to be battery and motor - "agnostic"... set up so I can easily bolt in different batteries and motors as I have the chance (another strike against the hub idea).
For now, I'm deep into the chassis reconstruction- collecting parts, sandblasting, cutting and doing all the usual R5/RD frame modifications, but that hasn't stopped me from fantasizing about motors and battery mounts. The motor/battery decisions will be driven by the fundamental nature of the bike... I have a twisted scheme up my sleeve that may fulfill all of that... if I can pull it off it will be everything the R5/RD was back in the day- fast, light and fun!

















Suzuki SP200, Mars Brushless, 300 Amp Kelly Controller,(18S12P) 