The principle of the additional hand drive

The hand drive should run in addition to the pedal drive.  For this purpose, two hand-drive levers are installed, which go synchronously to the right or left, and thus take over the steering of the trike or quad.  It is driven with the hands when needed, by moving one lever forward and the other reverse

Principle representation of a Nordic Trike with hand drive

a) Steering:
Swivel to the left means curve to the left and vice versa. This steering movement is cleanly separated from the drive movement via a double joint, so that no matter where the levers are swivelled in the drive direction, the same steering system is always created. The handles swivel typical +- 75 mm from the center line for steering.

b) Hand drive:
In the direction of travel, both hand-drive levers are connected in such a way that when a lever is moved forward, the other swings backwards. For the driver, this means that one arm performs a pressure and the other one exercise movement, connects it via the upper body. The swivel path to the drive is measured in such a way that about 250 mm swinging path correspond to half a pedal rotation. The hand-drive levers once forward and back pivoting, then corresponds to an entire pedal rotation. Since the hand drive finally couples into the pedal drive via freewheel castors, the driver determines how the hand movement is synchronized to the pedal movement. This allows you to realize both a movement similar to the diagonal step during cross-country skiing (e.g. right leg in front of, right arm back) and a large number of other combinations.

While the adjustment of the wheel to the body dimensions is basically easily achieved by adjusting the saddle height on a bicycle, the hand drive of the Nordic trike must also be adjusted appropriately.

So first the driver's seat is moved until the legs can operate the pedal drive well. This is usually the case if the knee is not completely pushed through in the pedal position at the lowest pedal position.

Now the swivel range of the hand lever is adjusted so that the arm is not yet very straight in the front position. The following table gives an overview of the dimensions we use.

Typical measurements of a  rider at a Nordic Trike

Overview of typical adjustment dimensions for hand and foot drive depending on body height