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.
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.
ngine 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.
