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Dual Freewheel Drive for Low Powered Vehicles

Introducing the Dual Freewheel Drive:

Dual Freewheel Drive 25mm axle
Dual Freewheel Drive Unit

The Dual Freewheel Drive is intended for use in very low powered and human powered vehicles where a conventional differential unit would be too heavy or costly.

These units can be used on velomobiles, quadricyles, trikes, cyclekarts, karts and small electrically powered or electrically assisted vehicles.

A variety of sprocket sizes or belt drive pulleys can be fitted.

The dual freewheel uses a two freewheel units mounted in a light aluminium housing.
The freewheels are threaded onto keyed bosses which transmit the power to the axles.

The standard unit is designed for 25mm OD axles with 6mm drive keys.
Other axle diameters can be accommodated using different sized bosses (max. axle dia. 25.4mm, 1″ )

The mass of the Dual Freewheel Drive unit is less than 1.5 Kg (without axles and sprocket).

Operation:

The drive from the chain or belt is transmitted to the housing of the dual freewheel unit via the sprocket or pulley.
In the forward direction, drive is transmitted to both axles via the freewheels.

As power is equally transmitted to the axles, this provides excellent traction on slippery or loose surfaces (a bit like a limited slip  or locking differential).
The freewheels will still allow either axle to rotate at different speeds during turns.

On overrun, the freewheels rotate allowing the drive chain and housing to slow down or stop whist the vehicle continues to roll forwards.

The drive chain cannot be used to drive the vehicle in reverse.

Sprocket side
Dual Freewheel Differential

Installation & Maintenance:

The unit is designed for axles supported in self aligning bearings.
The axles should be supported with bearings at the dual freewheel drive as well as at the wheel hubs.
The axles lock to the bosses of the freewheels using grub screws and the power is transmitted via the keys in the bosses/axles.

The axles should also be restrained via collars at the support bearings.

Axles can be supplied with full length key slots to facilitate the attachment of disc rotor hubs.
(a disc rotor is required on each of the axles).

The unit is fully serviceable by the customer and uses readily available freewheels.