Two years ago Bimota, a small specialist Italian manufacturer, launched an exotic sports bike called the Tesi 1D, which broke away from the traditional layout by using a swinging arm, instead of forks, to hold its front wheel. Now Yamaha has picked up the baton, becoming the first to put alternative front suspension into mass production - on a machine that the Japanese firm hopes will match the success of its long-running sports-tourer, the FJ1200.
Yamaha's design replaces the traditional fork legs with a single-sided aluminium swinging arm, which runs from the frame - a compact, C-shaped structure - to a pivot inside the front wheel hub. A single diagonal suspension unit smooths out the bumps. A second aluminium strut runs vertically from the front wheel hub to a junction box above the wheel, from where it is connected to the handlebars to provide steering.
The rest of the bike, including the rear suspension system, with its single shock absorber, is relatively conventional. Yamaha has, however, fitted the GTS with other hi-tech features, such as fuel-injection, a catalytic converter, ABS brakes and an advanced, effective thief-resistant ignition switch.
Its engine is the water-cooled, four-cylinder unit from the FZR1000 sportster, detuned from 125 to 100bhp. The FZR's motor is outstanding for its midrange power as well as for its output at high revs. Simply opening the throttle produces a strong, smooth surge of acceleration almost regardless of engine speed.
The Yamaha is a very fast, refined motorcycle. In top gear it pulls eagerly from 40mph all the way to its top speed of around 140mph. If its five-speed gearbox is used to the full, the GTS is as quick as almost any bike on the roads. It is the Yamaha's forkless chassis that generates most interest, however. At slow speed the front suspension is unusually compliant, soaking up small bumps with eerie efficiency. One drawback is that the bulky front swinging arm restricts the front wheel's side-to-side movement. This combines with the Yamaha's weight of 550lb to make the bike feel unwieldy in traffic.
Unlike conventional front suspension layouts, the forkless system is virtually unaffected by cornering and braking forces. That helps make the GTS supremely stable - particularly under heavy braking.
The forkless system allows only single brake disc instead of the normal pair; the GTS gets round the problem with a centrally placed disc and large six-piston caliper, which incorporates a sophisticated anti-lock system. Helped by wide Dunlop tyres, the big bike pulls up swiftly and safely.
Unfortunately, not all of the GTS is as well thought-out. Its riding position is roomy and comfortable, but the fairing is less efficient than some. And with fuel consumption running at between 30 and 40mpg, the GTS's range of between 120 and 160 miles is inadequate for a big sports-tourer.
So is Yamaha's GTS1000 the face of the future for motorcycle design? The forkless system certainly has worthwhile advantages, along with some drawbacks that may be minimised given further development. Yamaha's bold push towards the future is to be applauded, but the GTS1000 disappoints in some respects and comes with a high price of pounds 9,990. In the short-term, the GTS is unlikely to trigger a host of forkless models from rival manufacturers. Motorcycling's chassis revolutionaries have not won their battle yet.
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