At the heart of the drive train is the centrifugal clutch. Since monowheels suffer from the effects of "gerbling" under breaking, that is, when sudden deceleration is applied, the inner hub, along with the rider will have a tendency to roll backwards along the inner wheel. The worse case scenario occurs when the entire inner hub simply starts rotating around the inner wheel as the vehicle slows down, which is potentially (very) dangerous!
In an attempt to solve this problem, we've installed a clutch system which consists of an outer "clutch ring" and an inner spindle attached to the main drive gear:
Clutch ring (above) and spindle non-assembled (below):
Part of the spindle is fixed to the drive gear (yellow). Below is the spindle completely assembled:
Close up of the spindle, when the drive gear turns, the grey swing arms (made of strong ABS plastic) will swing outwards due to the centrifugal force applied. In turn, they will catch onto the inner teeth of the clutch ring, engaging the transmission and moving the vehicle forwards. Below you can see the clutch ring, now fully sanded: