2009 YZF-R1 takes the big bang approach
Torque of a V-twin, with the brute power of an in-line fourThe 2009 YZF-R1 has been unveiled by Yamaha and, as widely tipped, it has adopted a big bang style engine as found on its M1 MotoGP machine.
Yamaha isn't using the term "big bang" though, instead opting for less robust terminology -- "Crossplane technology". With each conrod 90 degrees from the next, the firing interval of the new engine is 270 - 180 - 90 - 180 degrees, achieved through the use of offset crankpins.
Yamaha claims the new firing order "all but eliminates undesirable inertial crankshaft torque, which allows the engine's compression torque to build smoothly and provide a very linear power delivery out of the corners".
In other words, Yamaha is banking on more controllable power delivery, particularly at low to mid rpm, which is not such a bad move for most mere mortals in an engine which is claiming 133.9kW (180hp) at 12,500rpm, with 115nM of torque at 10,000rpm.
Big bang engines generally place a lot more stress on engine components compared to a traditional even 180-degree firing interval, and a bigger crank journal (up from 32 to 36mm) has already gone some way towards compensating for that.
Each cylinder on the YZF-R1 has its own dedicated EFI mapping, and the machine also maintains YCC-T (Yamaha Chip Controlled Throttle) YCC-I (Yamaha Chip Controlled Intake) from the bike's predecessor. The pistons are the ubiquitous forged aluminium.
At 78mm, the bore is the biggest even seen on a Yamaha Supersport engine.
There is also a D-Mode selector on the Yamaha, with two separate maps to cater for different riding conditions, similar to what's been seen on Suzuki GSX-Rs in recent times. There is a switch on the handlebars to toggle between "A" (sporty response) and "B" (less responsive) modes.
The aluminium frame is also all-new, and there's a 4-2-1-2 exhaust system.
The forks now feature independent damping: the left fork takes ownership of compression adjustment, and the right leg rebound. There is high and low-speed compression damping on the shock absorber, as well as simple screw adjustment for preload.
Yamaha claims a wet weight of 206kg. Price, availability and colour choices are yet to be announced by Yamaha Motor Australia.
The YZF-R1 will be campaigned in next year's Superbike World Championship by the all-new factory pairing of Tom Sykes and Ben Spies.
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