November 12, 2008 Patents lodged by Austrian Competition Motorcycle Manufacturer KTM indicate that a hybrid 2WD dirt bike is not far away. Common sense dictates that a motorcycle with both wheels driven (2WD) will go around corners faster and with greater surety than one equipped only with the motorcycle’s traditional rear-wheel drive, much the same as 4WD cars offer superior traction to their rear or front wheel drive brethren. A lot of interesting development work has been done over the last decade with Yamaha offering Ohlins 2WD system on selected enduro bikes in Europe, Christini developing mechanical AWD (aka 2WD) kits for Honda and KTM dirt bikes and KTM talking publicly about its hydraulic 2WD development. Now it appears KTM is to employ a small electric motor on each wheel to supply additional torque when it’s needed. A recently filed set of patent applications heralds some exciting prospects.
Back in 2004, we wrote about KTM’s prototype hydraulic 2WD system which project leader Wolfgang Felber described as having a pre-set torque distribution between the front and rear wheel. He also commented, that although the system was already fairly well developed, it could “definitely be improved upon.”
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Having both wheels driven on road, trail or competition two-wheeled machinery offers many advantages. On almost any surface, 2WD offers better traction and stability, but it offers a greater advantage for slippery, wet or loose surfaces, on larger machines and is particularly useful for inexperienced and non-expert riders.
Interestingly, Kurt Nicol of KTM described the 2wd advantages extremely well here, and there’s an excellent account of testing the Yamaha 2wd system on MCNews.com.au – our take is that existing 2WD systems don’t quite offer enough advantage for the expert rider to be worth their additional weight – yet!
The additional weight of a hydraulic system makes it only a marginal advantage for an expert rider, and it’s only a matter of time before a suitable light weight electric motor is available that will offer far more sophisticated, (most likely computer-controlled) power delivery from the front wheel.
The bike pictured in the patent images has the shape of a desert racer - KTM has dominated desert racing for a decade - a desert racer will also be one of the most obvious beneficiaries of the design as 2WD offers much greater stability and better steering in deep sand.
Perhaps most significantly, this is the first time that a motorcycle manufacturer with genuine race credibility has moved into the electric/petrol engine hybrid area and if KTM does bring the 2WD hybrid to market, it will be entirely to gain a competitive advantage. KTM’s ethos is to deliver “ready to race” motorcycles, which guarantees that if it don’t work, it won’t be on its motorcycles.
Almost certainly we’ll see a lot more 2WD motorcycles in the next few years as electric motors develop and proliferate to accommodate the growing electric bike industry. One likely technology contributor to the field of 2WD via electrically powered front wheels will be the motor suppliers to the burgeoning electric bicycle industry which demands very lightweight in-wheel motors. Given that the front wheel of a motorcycle with 2WD needs roughly 15 % of total power, the power output needs for the front wheel electric motor are not that great.
Even more intriguing is the use of an electric motor in the rear wheel and the advantages this offers in delivering predicatable, linear torque at low speeds (perfect for KTM’s strength, it’s core dirt bike clientele) as well as the brutal horsepower of KTM’s entire dirt bike range.
Currently, there is only one commercially available two wheel drive motorcycle – the Rokon. The Rokon is a go-anywhere machine – with big wide tyres and both wheels driven, it’ll take people places that normal motorcycles can’t go (at least being ridden by people with normal skills) but it’s not a mainstream product.
There's also the Christini, which offers a mechanical 2WD conversion kit for 2004-present Honda CRF250R, CRF250X, and CRF450X models and KTM 250/300 2-strokes and 450/505 4-strokes. The Honda kit costs US$4000 and the KTM kit is US$4600.
Christini's patented mechanical All Wheel Drive system delivers power from the motorcycle transmission to the front wheel through a series of chains and shafts. To get an idea of the advantages of the AWD (aka 2WD) system, check out the testimonials for the Christini system:
“I came away impressed. In loose, rocky, sandy uphill situations, it's magic, a real advantage. There's a reason four-wheel-drive cars rule the off-road.” Ryan Dudek, Cycle World, April 2007
“The Christini bike worked really awesome on the muddy, icy, and rutted climbs. I just kept passing riders and taking harder and harder lines, looking for an opening to get by.” Geoff Aaron Racer X, March 2007
“Without the Christini it would have probably taken me at least an hour longer, and I would have had to take multiple tries at some of the climbs. The two-wheel drive saved energy and worked flawlessly.” Adam Booth, Dirt Bike, March 2007
“It was almost like cheating in the mud. There were riders stuck all over the plaec and I just blasted past with no problems. The difference is like going mud-bogging in a family wagon versus a purpose built 4x4. All-wheel-drive is the way to go off road and Christini's got it covered!” Derek Stealhy, Dirt Rider Magazine, October 2006
“This is it. This is the wave of the future. Once AWD bikes become available off road riding will never be the same.” Paul Clipper, Trail Rider, October 2005
“Plain and simple, 2WD is going to change off-road motorcycles in the very near future.” Jimmy Lewis, Dirt Rider Magazine, October 2004
Our favorite attribute is that "with the front wheel under power, it is nearly impossible to wash out the front end", and there are many other
The KTM patent applications can be found here.View gallery - 8 images