[Dadio]

Just a few pictures of the two speed installed and a little description of its function for those who are curious .


The way it works is with a double pinion on the motor that drives two spur gears , the larger spur for low gear is fitted to a one way roller hub that drives the spindle initially.


behind this there is an expanding clutch similar to the centrifugal clutch on a lawn mower although its not a true centrifugal clutch .

this clutch comprises of two semi circular shoes that are forced outward to engage on the inner surface of a drum to transmit drive , the drum is fitted to the other smaller spur gear for the higher gear , when not driven by the clutch the drum freewheels on the spindle on plain bearings , the clutch shoes rotate with the spindle and are forced outward by ball bearings that sit half in the shoe and half in a groove cut into the edge of a central hub that's locked to the spindle , two springs and screws hold the shoes inward around the hub and help control the rpm that a gear change happens .





As the central hub is spun faster the ball bearings move from the center of the groove toward the edge forcing the shoes apart and locking them onto the inner face of the drum , as i said its not a true centrifugal clutch but one operated by a rising ramp effect that's more torque driven .
Once the clutch engages it locks the smaller spur to the spindle for the higher gear , the larger spur is now over driven and so freewheels on the one way roller bearing that it was driving with initially .