Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/460339
FEATURE EVOLUTION OF THE YAMAHA YZF-R1 P82 Yamaha fitted the 2007 YZF-R1 with what they called the Yamaha Chip Controlled Induction system, or YCC-I for short. The YCC-I system acted by increasing the length of the intake fun- nels at low revs to increase torque and to shorten them at high rpm for more power. This system worked hand-in-hand with the new Yamaha Chip Controlled Throttle (YCC-T), a ride-by-wire throttle system that was a first for a liter-class production sportbike, although the YZF-R6 got this upgrade in 2006. Yamaha claimed the YCC-I was also a production first, however MV Agusta developed a similar system a couple of years earlier for the F4 Tamburini called the Torque Shift System (TSS), so Yamaha's claim is debatable. The system worked, but wasn't as smooth as Yamaha hoped. Power on the 2007 YZF-R1s is THE BIG BANG THEORY Most of you will remember the first time you heard a 2009-onwards Yamaha YZF-R1. That deep, throaty, lusty roar from the totally revamped 998cc inline four that was so far removed from the screamer firing order it may as well have come from Mars. The 2009 Yamaha YZF-R1 was a complete overhaul. It looked totally different and sounded unlike anything else on the road. Yamaha delved deep into its bag of tricks and brought the first Big Bang engine in their history to market. The cross- plane crankshaft meant that the pistons in the new YZF-R1 all fired at irregular intervals, rather than a normal four-cylinder engine that fired the pistons in pairs. The cross-plane crank saw each known to be peaky and thus not easy to get the best out of unless you were wringing the nuts off it. Bottom-end power was lacking, and even though it performed great up top, that wasn't where most road riders spent their time. And, like all good nemeses, Honda was one year away from launching their 2008 CBR1000RR, a machine so good they still haven't given it a full makeover. So Yamaha had an issue. They had a good bike, but something needed changing. They also had a MotoGP team that ran a four-cylinder engine, but one with a very different sound to the production bike. Hang on a minute… piston spaced unevenly and created a long-bang firing order, thus helping traction and accelera- tion out of corners via a smoother power delivery. This was Yamaha's golden advantage in MotoGP. Valentino Rossi used this engine format to win MotoGP titles in 2004, 2005, 2008 and 2009, while Jorge Lorenzo did it in 2010 and 2012. On top of the heavily revised bottom-end, the new en- gine gained a second fuel injector to help smooth out mid-to-high rpm throttle response, plus three different riding modes, something Suzuki had pioneered a couple of years earlier. The chassis was all new. The engine was now angled further back than before at 31-degrees, although it was 1998 2002 2004