Two Speed Gearbox Assembly:
Assemble the two speed clutch shoes. Fit the gearbox shaft and slide the 2nd speed drum over the clutch shoes. Tighten the centre Allen Screw to achieve o.2mm clearance between the shoes and the drum. Tighten the outer screws until the shoes lock the drum, and then slacken off each screw ¼ turn. Fit the gears onto the 1st gear one way bearing and the 2nd speed drum. Apply one drop of one way bearing lube to the 1st Gear bearing.

Note: There are three first and second speed plastic spur gears available to perfect your gear ratios.