Six and Seven Speed Hubs for Dual Freewheel Units
A six speed, Shimano geared, dual freewheel differential has been developed for a mid-drive electrically assisted tricycle.
This unit is intended to replace the existing one wheel drive axle on the rear of a trike to give better traction whilst retaining good turning characteristics.
This being important due to the increased power given by the electric assist mid-drive motor.
The original trike had drive to one rear wheel and the other freewheeled on its axle.
The incorporation of the dual freewheel differential fitted with the Shimano six speed hub enabled both axles to provide drive to the rear wheels whilst retaining the ability for a tight turning radius.
The Shimano six (or seven) speed gear cluster fits in the same position as that of the trike’s original axle and uses the same derailleur gear shift mechanism.
Due to having a differential the trike now required to be fitted with a brake on each rear wheel/axle rather than the single band brake of the original.
The dual freewheel differential unit uses 15mm diameter keyed axles on both sides.