Yamaha just moved the goalposts in the litre-class sports bike wars with a totally redesigned, third-generation YZF R1 for 2004. Right at the top I'll give you the two essential numbers:
134 kiloWatts
172 kilograms
"Wow!" is right.
The first figure comes from an even higher-revving 998cc, five-valve, transverse four with the previous motor's bore punched out to 77mm and its stroke shortened to 53.6mm – the result: maximum power at a stratospheric 12 500rpm.
The exhaust system is routed under the seat, a la Ducati, for maximum ground clearance
The compression ratio is up to 12.1:1 with bigger valves in the narrow-angle combustion chamber but a new closed-deck cylinder block reduces the cylinder pitch so that, although the bores are three millimetres wider, the width across the motor has increased by only 2.8mm instead of 12mm.
Continues Below ↓
The new fuel-injection system has motor-driven secondary throttle valves to reduce the slamming-door effect common to all spritzer-fed bikes with a 32-bit ECU for more responsive power delivery. It's also 27mm narrower than the previous set-up.
The clutch and six-speed gearbox remain vertically stacked behind the motor like all R-series Yamahas; not the best layout for a motorcycle transmission but it is definitely the most compact so lends itself to Yamaha's design philosophy of a long swing-arm inside a short wheelbase.
There's a high-efficiency curved radiator and a liquid-cooled aluminium oil cooler, direct-ignition "stick" coils integral with the plug caps and a high-output magneto for reliable ignition even when each plug is firing more than 100 times a second.
The motor is tilted forward so the main frame spars go over the motor instead of around it.
The exhaust system is routed under the seat, a la Ducati, for maximum ground clearance (Yamaha claims 56 degrees) and is all titanium, including the revamped EXUP valve, except for a stainless-steel mid-pipe containing the catalyser which runs too hot to be housed in any other metal.
Continues...
|
