Ticket To Ride

Sun Herald

Sunday June 25, 2000

BOB JENNINGS

If you thought an ashtray on a motorcycle was an interesting idea, Yamaha is about to push the boundaries even further, writes BOB JENNINGS.

WHILE all-wheel drive is all the go in the automotive world, with even the mundane shop-abouts boasting the feature, Yamaha has adapted the concept to the motorcycle.

It has developed an extraordinarily clever two-wheel drive system for a motorbike.

The concept has been demonstrated by the company's reigning 500cc world motocross champion, Andrea Bartolini, who has given it a glowing endorsement.

The immediate application is seen to apply to off-road machines, although given the automotive world's penchant for spreading anything that's new onto the maximum number of applications, don't be surprised if Yamaha follows the lead and its 2WD system is applied to on-road machines.

Yamaha has already hinted that this might be the case.

It's not so silly. It wasn't all that long ago that purists were also pooh-poohing the idea of ABS anti-skid brakes on motorcycles, too.

But don't start looking for chains and sprockets going to the front wheel. The drive system of the TT600R 2WD is hydraulic and is claimed to be light, although Yamaha doesn't say how much of a penalty the oil pump, driven by a chain on the side of the engine, and the associated plumbing and front-drive system add to the overall weight.

The advantage of the hydraulic system is that it allows the front wheel to turn from side to side and move up and down on its conventional forks in the normal way.

This isn't the first time 2WD on a bike has been tried.

During World War II the German army used BMW motorcycles and sidecars which had drive to the sidecar wheel.

And in the past few years, Australian Ian Drysdale developed a working version of the concept of a two-wheel drive motorcycle. Not only that, but he also worked on the concept of two-wheel steering. There is no indication that Yamaha is going quite that far.

Others have tinkered with shaft and chain drive to the front wheel, but weight and complexity have scuppered them.

Apparently the TT600R 2WD prototype has been under development for several years, and Bartolini has given it a fairly decent work-out, although he remarks it is different to ride it than a conventional machine.

The prototype has a production-based single-cylinder engine of 600cc which develops 33kW.

Yamaha's website quotes Bartolini as saying the machine was: ``Impressive. Very impressive. The bike is so easy to ride. I tested the TT600 on sand and found that on the fast sections the front wheel is always in contact with the ground, aiding traction and control at the front.

``It is so stable not a hint of the shake you normally get through the handlebars."

He also said that the machine was impressive through twisty sections, being able to turn more quickly, although ``it takes a bit of getting used to because as you open the throttle in a tight turn the traction is so good that it takes you off what you think is the ideal racing line". Now that could be interesting.

Yamaha's immediate goal is to give its endurance racers an advantage, especially in sand, loose stones and shale and Bartolini said he could foresee advantages for road users.

``Anything that improves stability, traction and balances the power delivery has to help non-professional riders when they ride on the road or through the dirt," he said.