Yamaha was once among the select group of companies to have built a 2WD production bike. It was called the WR450F 2-Trac. Made in tiny numbers, the two-wheel-drive Yamaha used a hydraulic Ohlins-developed system to power the front wheel. As ever with two-wheel drive, riders who questioned about the system were full of praise for its performance and the extra security it offered, particularly in wet and slippery conditions, but apart from the WR-F, there were no production spin-offs.
Apart from Yamaha, other brands like Suzuki, BMW, Ural and KTM too have had their shot at getting an AWD motorcycle, of which, Christini is the only one currently that can give you a 2WD experience on their rally/dirt motorcycle swaps. They use a second chain that drives a transfer box placed above the engine which powers the front wheel via a pair of telescopic shafts.
A similar mechanical unit also drives the front end of the DT-A prototype where the drive of the front wheel via a chain that runs parallel to the rocker and is mounted in both swing axles. At the engine, the output is via a belt system that picks up the drive torque via a freewheel directly on the pinion.
To keep the engine from excess load, the system will send power to the front wheel only when the rear wheel experiences slip or loss of traction past 5 percent. When that happens, the sprocket sends power to the front wheel immediately. Koch has also ingeniously added a switch that will cut-off power to the front wheel when not required. This will help the engine perform more efficiently when the bike isn’t off the road.
The steering system on the DT-A is via a trailing arm and an auxiliary linkage. It has a unique homo-kinetic joint so that the power transmission to the front wheel runs smoothly even with larger steering angles. The front swing arm is supported by a strut directly on the newly drawn mainframe. Steering head angle and caster are adjustable.
With all this happening, the KTM 990 DT-A surprisingly weighs 89 pounds lesser than what it did before the strip down. The DT-A holds a total of 7 gallons of fuel distributed amongst three tanks for those enduro rides off the road.
Koch has applied for patenting his invention and has around 270 engineering drawings and casting tools all ready for a full-scale production. He is on the lookout for investors to help him set up an assembly process.
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