Hi, this may be an obvious problem but my xr3i vibrates very heavily at around 70mph. i noticed it after buying it and driving it home, the front wheel was severly buckled so i moved it to the rear. I assumed this was the problem but have also noticed a small notch about 7mm long and 2mm wide on the longer drive shaft, do you think that when this notch was created it caused the drive shaft to bend and thus cause the severe vibrating or is it down to the buckled wheel? thanks