Facts

DT-A is the prototype of an all-wheel-drive motorcycle to be used as an adventure enduro, or at rallyes. DT-A was developed over a period of 10 years. Except for a few standard-type components, such as the engine, the rear wheel including the swing arm, and the brakes, the motorcycle is our own design and product. The aim was to provide a fully-fledged additional front wheel drive for motorcycles of every performance level. Enough power should be transmitted at every speed. With normal use, handling the motorcycle should not be impaired .

The result is a motorcycle that differs strongly from a conventional design with a telescopic fork. With our DT-A the front wheel is guided by a swing arm which also brings up the transmission. In order to realize all the advantages of the concept, almost every component had to be re-designed and re-arranged, beginning with the mere frame. Thereby the DT-A can tap the ful potential in terms of lightweight design and mass centralization, after turning away from the telescopic fork. Compared to the motorcycle used for reference, the KTM 990 Adventure, the weight could be reduced by no less than 40kg .

The front wheel suspension

The front wheel is guided in a swing arm .The steering axis is spanned by two ball-and-socket joints, whereas the first one is centralized in the hub of the front wheel and the second one is positioned above the front wheel. The former is carried out as a specially developed constant velocity joint, of which the output shaft is fixly connected to the front wheel. The input shaft is lead out parallel to the rear wheel centerline and pivoted in the swing arm. It is coupled to the transmission output shaft via belt drive and chain drive. A free wheel clutch in the drive train is engaging the transmission to the front wheel automatically as soon as the rear wheel’s slip excels 5%. That means under normal driving conditions ,i.e. on tarmac, the front wheel is moving along without being driven. Not before the rear wheel loses traction, the transmission will be clutched in. With a lever at the handle bar one is able to permanently disconnect the transmission. Because of the stable purely mechanical drive train without detour the efficiency of the DT-A is very high and there are no problems deriving from energy loss at high speed / high performance

The drive joint

An ‘obvious’ cardan joint would not be suitable to transmit forces, since pulsating torque oscillations would appear with increasing steering angle. These oscillations would retroactively effect the steering and the drive train. Also the layout of automobile constant velocity joints would lead to a resetting momentum to the steering because of the high friction inside the joint. The DT-A makes use of a specially designed constant velocity joint, which transmits the driving torque with low friction. Only this development facilitates high steering angles (carried out up to 35°) without generating pulsating torque oscillations with repercussion to the steering. This constant velocity joint provides for transmission of high performance at low weight, the unsprung masses are comparable to a conventionally suspended front wheel. The steered masses are significantly lower.

Engine

KTM LC8 990 Adventure 74kW (100HP)

Frame

triangulated tubular frame, welded on a specific fixture

Tanks

Aramid Honeycomb-Sandwich

Fairing, seat support

Carbon Honeycomb-Sandwich

Front wheel suspension

swing arm guided front wheel

Upper lever

Carbon unidirectional laminate

Swing arm

artificially aged aircraft Aluminium alloy

Weight ready for use without fuel

170 kg

Unsprung masses, front wheel, rotating

12 kg

Unsprung masses, front wheel, non-rotating

4,8 kg

Tank capacity

27 l in 3 tanks

Suspension travel F/R

280 mm / 280 mm

Rake angel/ ground trail

adjustable

Seat height

1000 mm