Re: Secure mounting.
With respect... rubber mounting a motor to a bicycle frame is a bad idea. You may feel less vibration, but it actually creates more violent vibration on the frame and will cause the frame to crack and/or break. The best way to reduce those bad vibes is to securely mount directly to the frame metal on metal. Ideally clamping 360 degrees around the frame tube, and replace those cheap studs with high grade studs or SHCS's.
The picture demanstates a good solid frame mount with a custom clamp that I made.