A typical four-cylinder engine uses a flat-plane crankshaft, and the two outer
and two inner pistons rise and fall in pairs, firing 180 degrees apart. Torque
is applied to the crank during combustion, of course, but also from inertia as
the crankshaft rotates. This inertial torque is seen as noise to engineers, and
it has the effect of confusing a rider about the amount of traction available
from a bike’s rear tire.
The same holds true in the world of MotoGP racing, so Yamaha engineers
introduced in 2004 an uneven firing interval for its inline four-cylinder M1
with what’s called a cross-plane crankshaft. In this new design the pistons are
arranged 90 degrees apart from each other around the crank, which eliminates the
inertial torque fluctuation of a typical four-cylinder mill. A balance shaft
keeps vibration at tolerable levels. Yamaha has adapted this configuration to
its R1 streetbike, providing enhanced traction and a very distinctive exhaust
note we’ve been hearing from Valentino Rossi’s racebike.
In the 600cc and 1000cc supersport categories, the successful mantra has always
been lighter weight and more power. But with a claimed 182 crankshaft
horsepower, the new R1 doesn’t re-set the bar in power production. And its 454
lb running weight (full of fuel, etc) is 15 up on the svelte Honda CBR1000RR.
The R1 and its new engine configuration instills confidence to its rider.
Other than the brake calipers, pretty much everything you see here is new to
Instead, Yamaha has focused on its stated concept for the R1: “To deliver a
maximum amount of drive force in the smoothest manner possible.” We’re happy to
report that this isn’t just some PR hype - it’s actually something a rider can
feel after just a short time in the saddle.
One of the knocks against the old R1 was its lethargic response when leaving
stoplights. The new engine’s beefed-up midrange sure helps in this regard, aided
by two extra teeth on the rear sprocket. Quick launches no longer require major
clutch slippage, making around-town riding much easier to manage.
In terms of its chassis, the R1 doesn’t break as much new ground as its engine.
Rake and trail remain unchanged, while the wheelbase is shortened by a scant
5mm. Nevertheless, the R1’s frame is an all-new design with a significantly
revised rigidity balance.
Made from a mixture of gravity-cast, CF-cast and pressed-sheet aluminum, the
frame is stiffer at the steering head and swingarm pivot, but its perimeter
frame rails are now 37 percent more flexible laterally, providing greater
feedback when the bike is leaned over in a corner. The swingarm also had its
rigidity balance tweaked, allowing more flex laterally and torsionally.
Around the Eastern Creek circuit, the new R1 proved to be quite cooperative.
Turn-in response is about what we’ve come to expect from a literbike, aided
somewhat by the use of a taller 55-series rear tire rather than the typical
190/50-17. There are several mid-corner bumps around the Aussie racetrack, and
the Yamaha was quite adept at sucking them up without throwing the bike off its
Helping keep things stable is a nifty steering damper. Like the previous model,
the damper has a check ball that engages when the handlebars wag back and forth
too quickly. This mechanical system is aided by a new electronic component that
engages a damper valve when vehicle speeds surpass 125 mph or when the throttle
is twisted past the halfway point.
Even with street tires, the R1 encourages acute lean angles. We rode on
Michelins, but US models will be fitted with Dunlop’s new D210 rubber.
A totally new suspension system is up to the task of smoothing out the ride. Up
front is a Soqi fork that has its damping circuits divided between each leg. Oil
flow is simplified by having the left leg handle only compression damping and
the right tube controlling only rebound damping. Yamaha reps claim this design
minimizes cavitation (air mixing with the oil). At the rear, a bottom-link
suspension has a more progressive ratio to make fuller use of its travel, and
the addition of a hydraulic preload adjuster makes setting up the bike easier.
A revision to the engine architecture allowed it to be placed further forward in
the frame, shifting the weight distribution slightly towards the front end. To
best centralize mass, fuel is now carried lower between a rider’s legs and a
lightweight magnesium subframe replaces an aluminum component.
Cross-plane Crank For Next R6?
Since the R1’s new firing order appears to be successful, it begs the question
about whether this system can be incorporated into Yamaha’s 600cc sportbike, the
YZF-R6. So we questioned the R1’s project leader, Toyoshi Nishida, about whether
we might see this configuration in the middleweight screamer.
The R1’s project leader hinted that the next R6 might feature new engine
technology that will enhance a rider’s feeling for traction at the rear tire.
He told us that because a 600’s power output isn’t nearly as potent as a
literbike’s, racers in the smaller class usually apply only full power, so the
cross-plane’s part-throttle benefits wouldn’t be so obvious. He added that the
counter-balancer necessary with the cross-plane arrangement would sap some
power, hence it wouldn’t be the most efficient way to provide that direct
connection to rear-tire traction for a 600.
However, he hinted that there is another way to aid rear-tire traction, and one
that doesn’t involve electronics. Curious about what he referred to, I asked if
there was the possibility of using a single-plane crankshaft arrangement in
which the two paired pistons fire at the same time (instead of 180 degrees
apart), similar to a project used a few years ago in the British Superbike
championship on a Yamaha R1. That engine proved to work well in wet conditions,
but it was soon outlawed by race organizers.
Nishida-san’s response indicated I was barking up the wrong tree, but any loyal
engineer would naturally want to keep information like that to himself. Whatever
the case, we may see something special in the engine compartment when the next
R6 is revealed.
When it comes to slowing down, the R1 has an upgraded braking system. Although
the front brake discs are 10mm smaller in diameter (310mm), they proved to have
excellent power and feel. They still use six-piston, radial-mount calipers, but
the rotor carriers are now more rigid.
There is only one really heavy braking zone at Eastern Creek, but the R1’s
brakes demonstrated terrific feedback and were easy to modulate. A ramp-type
slipper clutch aided corner entries, allowing quick downshifts without worrying
about the rear tire locking up during compression braking. A new gear-position
indicator lets a rider keep track of what’s going on in the transmission.
Yamaha has joined the electronic engine-control bandwagon by incorporating a
D-mode selector that allows a choice of three engine-response maps. Unlike
Suzuki’s DMS, Yamaha’s system does not affect ECU settings - the performance
curve of the engine always stays the same, and it’s only alteration is the
response from Yamaha’s Chip Controlled Throttle (YCC-T). The default Standard
mode is said to be optimal. The A-mode provides sharper initial throttle
response but the same performance as Standard up top. Response from B-mode is 30
percent slower at all throttle settings.
Unlike most sportbikes’ dual headlamps, both of the R1’s projector headlights
remain lit in both high and low beams.
In practice, I preferred the Standard mode, as it allowed smooth response that
was amazingly cooperative. A-mode made throttle application a bit touchier but
still quite manageable. B-mode provided more leisurely responses that weren’t
ideal for cutting quick lap times, but it would be a good choice when road
conditions are a bit dicey, such as during damp or wet conditions. Unlike
Suzuki’s system, engine response isn’t neutered to 600cc-class power levels.
Getting the power to the pavement is easy thanks to the R1’s new motor.
The R1’s Mikuni fuel-injection system now incorporates the latest 12-hole
squirters, augmented by secondary injectors. As in the previous R1, Yamaha’s
variable-length inlet tracts (YCC-I) help broaden its powerband. The intake
funnels stay in their long form below 9,400 rpm, then flip open to their shorter
length for enhanced top-end pull.
Yamaha says the R1 produces 182 hp at 12,500 rpm, which should be enough for
anyone riding on the street. But ratcheting up through the gears along Eastern
Creek’s front straightaway, the Yamaha’s upper-rev pull didn’t feel as
mind-numbing as something like the Kawasaki ZX-10R. Either this new engine’s
broader powerband made it feel a bit duller or its ultimate peak power isn’t as
plentiful as its burliest competition. Regardless, for a streetbike application
this distinctive new engine configuration is much preferred over the previous
And the engine output doesn’t hurt the R1’s racetrack performance, either.
Yamaha’s test rider Jeffry de Vries was able to lap Eastern Creek in the 1:37
range on the latest R1. On the previous model, his best lap was in the high 1:39
range. This bodes well for American Ben Spies who will be riding the Yamaha in
the upcoming World Superbike season.
It should be noted that American-spec bikes produce six horsepower less than
Euro versions thanks to smaller muffler internals that keep noise within US
limits. The exhaust system continues its four-two-one-two configuration, exiting
into dual underseat titanium mufflers, but it now goes without Yamaha’s EXUP
A large cutout in the side fairing allows hot air to escape. Titanium mufflers
look a bit bulky.
In terms of street use, the R1 now offers a slightly more hospitable riding
position. Its handlebars are 10mm closer to the rider, and the seat is placed
8mm forward. Footpegs are situated 10mm forward, and they are now repositionable
15mm up and 3mm rearward. Only truly fast riders will need the pegs in their
more aggressive position.
In my decade-plus career in moto-journalism, I’ve had to sift through reams of
PR propaganda to discern mostly incremental increases in performance of
sportbikes. Lose a few pounds here, add a couple of percent horsepower there. So
it was with great delight that I found a palpable shift in technology when
testing the new R1 that provides a real-world advancement in engine design.
Arriving at dealers at the end of this month. The Team Yamaha Blue version
retails for $12,390. An extra $100 will buy either of the others, each with
matching pinstripes around their wheels.
Believe the PR hype this time around. Yamaha’s new YZF-R1 provides literbike
performance in a package that benefits not only racers, but also lesser-skilled
street pilots. With the addition of the cross-plane crankshaft engine, it’s safe
to say that Yamaha has upped the ante in delivering mega performance in a
package that will benefit riders of all types. And it sounds marvelous.
Good on ya, Yamaha!