I took the Ezip framed bike for a 2 mile ride and found it to be more spooky at top speeds than the "flexi" cruiser. Go figure. Also still had that stumbling problem.
Came home and stripped it down and threw the frame in the backyard. Put the motor on a Huffy Stonehaven. It actually feels better, but still has that stumbling. I finally took a risk and looked down between my legs at the motor and mount. I noticed the whole rear end oscillating during the stumbling episodes. I figure, just the fact that the motor is mounted at the end of a flat plate, then mounted to a light rear tube frame is not conducive to higher torque. The 24 volt rig is fine, but the 36 may be over powered for just about any bike with a "Y" rear end, which is virtually all bikes. A high torque system might be better as a center mount and run through the pedal gears, as a friction drive or a pusher trailer. Can't think of anything else to do but go back to a 24 volt system. That means having to order a couple of 24 volt controllers. Honey????.....................
Another option is to maybe mount the motor to a "softail" mountain bike. The one I have sitting around has an aluminum frame with a steel softail frame. Might be less prone to oscillation under
stress. Hmm...
Me thinks I'm going to take a break from this system for awhile and go play with that 24 volt 350 watt hub motor I have sitting against the wall. Bump it up to 36 volt and see what it can do. At least I'll have more space over and around the rear wheel to mount the extra battery. I'll also be able to use my original cruiser, which I like very much.
Back to the drawing board and strip this bike down and get ready to prep the next one.