Yamaha’s all-new 189 bhp, US$11,600 YZF-R1 Supersport

The R1’s reshaped combustion chamber runs with a higher compression ratio of 12.7:1, and the valve angle has been revised to 24 degrees – the same angle that is used on the 2006 R6.

For 2007 the R1 utilises an all-new four-valve cylinder head design developed from the advanced technology seen on our YZR-M1 MotoGP race bike, and features two 31mm diameter intake valves, and two 25mm exhaust valves. The two intake valves are manufactured from titanium for reduced reciprocating weight, which promotes the increased intake valve lift featured on the 2007 engine. And to ensure efficient high-rpm operation, the R1 runs with lightweight VX alloy valve springs which are designed to handle continuous high-load riding conditions.

These changes to the cylinder head design maximise the benefits of the new YCC-I and YCC-T by ensuring greater air intake volume at all engine speeds. In addition, the revised valve configuration and angle give reduced valve recess compared to the 2006 model, which makes for a smoother piston head shape. The result is extremely high levels of combustion efficiency which contribute greatly to the new engine’s stronger and more linear performance throughout its wide operating range.

New slipper clutch

The new R1 is designed to deliver the ultimate supersport experience on both the road and circuit, and in order to ensure a smoother approach to the apex of turns, a slipper clutch is fitted. This system shares the same structure as that found on the limited-edition 2006 YZF-R1SP model, and is designed to limit the amount of back-torque transmitted from the rear wheel through to the crank. This race-developed system improves traction during rapid deceleration and hard braking, and enhances engine and transmission reliability.

New design dual elliptical mufflers

The 2007 R1 is equipped with a completely redesigned exhaust system featuring an optimised length, expansion chamber and pipe sizes, while the new-shape mufflers have a fresh and impressive appearance. The mufflers’ cross section is an oblate elliptical shape which appears to lift the rear cowl, giving the higher-powered fifth-generation R1 a more masculine and aggressive profile. From the rear, the mufflers form a V-configuration to give this remarkable new bike a unique looking tail-end.

High performance ignition coils

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