Inline-four as we know it on last legs.
BACK in 1998, Yamaha turned the world of superbikes on its head with the YZFR1.
It was the lightest and fastest production sportsbike to take to our roads yet.
Eleven years later and Yamaha's done it again, revolutionising the litre bike class with the all-new R1 that's unlike any other motorcycle on our roads. Or racetracks! Sit on the R1 blindfold, fire it up and blip the throttle and you'd put your mortgage on it being a V-twin. The sound, the feel, the vibes are so unmistakably twin-cylinder, and the sensation continues as you get going at low revs. But pick up speed to hit the midrange and you'd swear it's a triple.
There's still so much torque, but with an engine that revs more freely than a twin. This has you believe that power will tail off as you climb higher up the rev range. Instead, it turns magically into the screaming inline four-cylinder you always expected the R1 to be. Talk about best of all worlds.
There's a superb connection from the throttle to the seat of your pants all the way to the rear tyre. You can feel the tyre dig in, giving you confidence to get the power down early and h a r d.
The engine is so tractable you can use first gear or sixth gear around Brands Hatch's tight Druids corner and still make good progress, an invaluable trait for the roads. There is no other bike like it.
The secret to Yamaha's unique power characteristics is the engine's crossplane crankshaft with its irregular firing intervals.
The crossplane crank has its pins set at 90, instead of at 180, as on a more traditional engine.
And with none of the four pistons hitting top or bottom dead centre at the same time, the crank's inertial torque is non-existent. This means the crank spins smoothly rather than in little jerks, and this smoothness is passed on to the rear tyre.
The rider is left with that excellent connection that lets them lay down more power sooner out of corners.
Engine braking is also greatly reduced on the R1 compared to a regular 1,000cc inline-four cylinder machine.
This is coupled with the best production slipper clutch I've ever experienced that must be on its way to putting aftermarket slipper clutch manufacturers, such as Sigma, out of business.
The brakes have an instant bite and progressiveness, and you need them to be this good because you run into corners much faster than you'd expect with so little engine braking.
Physically, Yamaha's R1 feels like a 600, not a big 1,000cc.
Climb on board and the mass disappears; the bike's a dream to fling around a tight racetrack. I wish it looked like the 600, too.
Yamaha's 600cc R6 is gorgeous, but I don't like the R1. The fairing's bitty, the two bulbous headlights look weird and the under-seat exhausts are so yesterday. The R1 is beautiful to ride, just not so beautiful to look at.
Yamaha's revolutionary YZFR1 is not cheap at pounds 10,000, but if you consider the technology it packs then it's not expensive either. And this is how all manufacturers will build their 1,000cc superbikes from now on.
The inline-four, as we know it, is on its way out..
Beautiful to ride - the Yamaha YZF-R1