[Drivencrazy]

Just a word of caution: An input torque on the "output" shaft can cause a significant amount of stress in the gearbox casing leading to cracking.

For instance someone pushing you from the front or rear would create a reactionary torque in the wheel. Which would then get transmitted through the gears and into the worm gear shaft which would press against the plastic housing of the gearbox.

We sourced some of these from Torque Trans for the 2011 season and had a similar issue arise several times.