Tuesday, January 20, 2015

NEW METAL 2015: Yamaha YZF-R1


Times have been hard for motorcycle manufac­turers and, up until recently, new models scarce. Now it’s time to begin again, and Yamaha is doing it in a big way with a revolutionary new YZF-R1 and limited-production YZF-R1M. The first wave of motorcycle electronics came from Europe, but the second wave—this Yamaha with its MotoGP-inspired suite of lean-angle-sensing Traction Control, Wheelie Control, ABS plus linked braking, and Slide Control—is profoundly greater.
Times have been hard for motorcycle manufac­turers and, up until recently, new models scarce.

The first wave brought us Band-Aids for specific problems, but Yamaha has centralized all capabilities by placing a “six-axis” Inertial Measuring Unit (IMU) on both of these models. The IMU, which would fit on your palm, contains gyros to measure rotations around all three axes (roll, pitch, and yaw) and accelerometers to measure rate of speed change along each axis. This is the technology of an ICBM’s inertial guidance, miniaturized and made affordable. In our own inner ears we have similar functions, which is why we can close our eyes in the shower and not lose our balance.

With the IMU’s measurements, the bike’s ECU knows the bike’s angle of lean, knows if it is pitching nose down or nose up and exactly how fast, and knows almost instantly (recalculating 125 times per second) if the back of the bike is swinging out from too joyful a throttle movement. Knowing the lean angle adjusts the multilevel traction control for the reduction in available tire grip caused by cornering. Nose-up pitch signals “wheelie in progress,” and the system smoothly controls it through throttle by wire.

“Yamaha can sell this whole motorcycle, with these systems on it, for less than the AMA’s electronics price cap,” Yamaha Racing Manager Keith McCarty said. The AMA had set an $18,000 cap on roadrace electronics, but the MSRP for this R1 is $16,490. This has been the story of digital systems; expensive to develop initially, they become almost ridiculously cheap once produced in quantity. Think of phones and computers.

Remember this: The closer a manned system approaches its limits, the more human capabilities stand out as the limiting factor. As in combat aircraft, the more details that are handled by electronics, the better the human opera­tor can get on with higher decision-making.

I asked Yamaha Product Planning Director Derek Brooks how it feels to ride a machine with such an integrated control system: “Most surprising to me is that this bike is smaller, lighter, and more powerful (than the previous model), but the systems are almost transparent,” Brooks said. “There’s no feeling of anything strange happening. You’re riding a very controllable motorcycle.”

Engine and chassis are new. The 998cc inline-four, a four-valve engine with a 79.0 x 50.9mm bore and stroke, retains the “crossplane” (crankpins at 90 degrees to each other instead of the traditional 180) crankshaft that the R1 inherited from the M1 MotoGP engine. Short-skirted “ashtray” pistons can be this light and thin because they are cooled by oil jets. Compression ratio is a torque-boosting 13.0:1, made possible by the accurate dimensional control of CNC-machined combustion chambers. Valve actuation has been switched from bucket tappets to lighter, F1-like finger followers. Power goes to the six-speed gearbox via an “assist slipper” clutch, which, in addition to smoothing corner entry, uses engine torque to increase plate-clamping force during acceleration. Claimed output is “approximately 200 hp.”

In a first for the industry, Yamaha has developed fracture-split titanium connecting rods. Titanium can be alloyed to equal the strength of high-tensile steels but has only six-tenths of the density of steel. That translates into reduced bearing loads, a bit less friction loss, and faster throttle response. The fact that Yamaha invested the R&D to produce such rods in quantity tells us this bike is not a homologation special. It is the future.

An all-new Deltabox chassis gives a 10mm shorter 55.3-inch wheelbase for quicker chassis response. Titanium headers and an under-engine titanium muffler canister save weight, as do magnesium wheels. To make room for the canister, the aluminum swingarm is top-braced.