We have to admit, we like the idea of two-wheel-drive (2WD) / all-wheel-drive (AWD) on a motorcycle. Provided that issues like extra weight and steering/suspension response are taken care of, a powered front wheel on a bike should make for extra traction and could possibly redefine the whole riding experience. There have been some well-publicized attempts at using AWD on bikes in the past, though there doesn’t really seem to be any interest in this from mainstream motorcycle manufacturers. We don’t know if that’s because AWD technology is too expensive or too complicated for production bikes but whatever the reason, we do think it’s a pity that no manufacturer seems to be interested in developing this technology.
Now, while mainstream manufacturers aren’t interested, talented individuals continue to work on AWD bikes and the latest such machine that we’ve come across is the Lawson all-wheel-drive bike, which is based on a production-spec KTM 300 EXC. With AWD equipment (front drive chain, sprockets, U-joints etc.), the Lawson bike still only weighs about 13 kilos more than the stock KTM and its creators claim that the bike is easier to ride off-road, climbs steep and rocky hills more readily and steers better in sand, mud, snow and loose rocky terrain. They also say the bike is ‘greener,’ since it ‘surmounts obstacles by traction, not by digging trenches.’
“As both wheels are pulling to surmount obstacles, the Lawson design motorcycle does not require speed and aggressive spinning of the rear wheel. As a result it is much greener, doing less damage to the terrain, and it can be much more easily walked through narrow backcountry trails such as those used by firefighters or rescue personnel. The advantage of an all-wheel-drive motorcycle is similar to why a four-wheel-drive vehicle is much better in difficult conditions than a two-wheel-drive vehicle,” claim the bike’s creators on their website.
At the front, the Lawson AWD bike uses a Hossack dual A-arm suspension set-up, which doesn’t compromise on the original KTM’s steering lock value, and has no torque- or bump-steer. “The double-A arm suspension is anti-dive when braking, with 1/3rd of the dive of a telescoping fork, and also anti-rise when powered. Anti-rise means that the front wheel won’t hop when it hooks up as a conventional telescoping fork tends to do. The 300mm travel suspension has progressive rate adjustable damping shock absorber spring/damping characteristics – the same as telescoping fork designs. It has no torque steer which means there is no interaction between torque to the front wheel and the steering. The drive system also reduces front wheel lock-up dramatically when braking. When the front wheel starts to lock up, the system engages the engine and rear wheel to keep the front wheel spinning past slick spots and as a result automatically balances the braking between the front and rear tires,” says a note on the Lawson AWD bike’s official website.
“The Lawson all-wheel-drive motorcycle design uses a mechanical drive design that is much simpler and more rugged than other AWD motorcycles. The drive system can take full power when necessary, and incorporates an overrunning ratchet to allow the front wheel to rotate faster in corners and on hard ground. The gearing between the front and back wheel is set up to provide as low as 1% rear wheel slip before engaging making it essentially full-time AWD, field adjustable by changing the front sprocket. The drive system only requires two chains and a U joint, making it much simpler and less expensive than other designs with equivalent suspension travel,” says the official website.
We really do think this is a fascinating machine and we’d love to see this AWD technology on a litre-class superbike or even on a 600cc supersports machine. In our opinion, AWD seems to have the potential for making streetbikes/superbikes significantly faster in the bends and also, possibly, safer and easier to control. “AWD on a sport bike would only benefit steady-state acceleration if traction is bad enough that the bike is no longer wheelie limited. An AWD sport bike would have all the handling and braking benefits. It would also free up some design constraints on wheelbase and rider ergonomics giving more styling freedom. Basically, the benefits to AWD are biggest off-road so that's what we built first. Still, I'd love to see what the current prototype would do on a set of supermotard tyres,” says Marty Lawson, who’s created the off-road AWD bike you see here. “Mainstream manufacturers are not interested in AWD or different front suspensions because of 'not invented here' and corporate inertia, i.e., what they build now is 'good enough' and profitable, why should they take a risk and make revolutionary changes,” he adds.
Well, while we understand that it won't be easy to persuade sportsbike manufacturers to go the AWD route, here’s hoping somebody will see a big enough advantage here and maybe undertake to develop AWD technology for streetbikes.
Pics: NewTech Development LLC’s Flickr stream
Videos of the Lawson AWD bike in action. Impressive stuff