Today got new wheels with 64mm diameter (compared to 48mm before).
This is the middle diameter wheel of these three wheels -- 85mm will be sent when available again 
I thought the wheel hole was a perfect fit for 12V motor axis -- it was not
LiPos were not fully loaded, only 11.23V compared to >12V.
Here is just the high speed accident with 5.7m/s or 20.52km/h at quarter speed on rowvid.com -- impressive:
http://rowvid.com/?v=88il0haKo6c&t=23&s=0.25
Youtube text copied in for completeness:
2nd High speed accident with new 64mm diameter wheel.
Thought that wheel was a perfect fit for motor axis
Wheel got lost at 0:23, wheel hole was too wide for the speed/force.
Rowvid.com frame by frame analysis with new wheel diameter:
Just before accident 6 rounds in 1.4s gives 4.3rps or 257.1rpm.
Wheel moves 1.33m per round giving 5.7m/s or 20.52km/h.
Hermann.