as a follow up to my previous posting (6th may) my wife is quite delighted with her Ezee Chopper which is a perfect size for her .Onbike was a pleasure to deal with and extremely fast . The only reservation is its maximum speed of 13mph . Does anyone have any experience of derestricting choppers . Is it possible ? Does it invalidate the warranty ? Its clear that the motor cuts out at 13mph so I don't think its about the 20 inch wheel size alone .