VOLUME 59 ISSUE 40 OCTOBER 4, 2022 P117
the seat—like the Fireblade had—
were regarded as unnecessary.
Anything that didn't need to be
there was scrapped. The 998cc
R1 was designed to be the light-
est, shortest and most power-
ful machine ever created in the
1000cc class. It was designed
to handle with the agility of the
company's YZF600 ThunderCat
(then its leading Supersport 600
machine) but have power levels
normally reserved for factory
WSBK riders Scott Russell and
Noriyuki Haga. A sports-tourer
the R1 was not.
A C LEAN SHEE T
OF PAPER
The mid-'90s was a bleak period
for Superbike sales, and Yamaha
realized that although the long-
standing YZF750 was a good
performer on track, the sales
success didn't reflect it. As such,
designer Kunihiko Miwa was
given a clean sheet of paper to
build a new Supersport machine,
right around the time the Yamaha
YZF1000 ThunderAce was given
a freshen-up in 1997.
The ThunderAce had always
been a reliable performer for the
Tuning Fork brand, and the 1997
version was indeed a fine ma-
chine. It had plenty of power from
the five-valve, transverse four-cyl-
inder engine that could trace its
heritage to the FZR1000 of 1989,
with a well-balanced chassis and
good ergonomics—but it still be-
longed in the Suzuki GSX-R1100
weight class and would hardly do
as a racer with lights.
That being the case, Miwa-san
took the basic YZF1000 engine
and pulled it to pieces. The R1's
engine was still to retain the com-
pany's sacred five-valve cylinder-
head, but that's about where the
similarities between it and the
ThunderAce ended. Miwa-san
concluded that the traditional en-
gine layout where the crankshaft,
driveshaft (countershaft sprocket)
and mainshaft were all in a line
represented a drastic waste of
space, so he came up with the
"3-axis" design, where the main
shaft was offset and positioned
above the crank and countershaft
sprocket, closer to the crank.
This new design was soon ad-
opted by the industry and is now
the only way to go if you want to
build a serious across-the-frame
four-cylinder Superbike. The new
design also meant the clutch
could now be mounted higher,
with the cylinders and crankcase
cast as a complete unit. This also
allowed Miwa-san to turf the tradi-
tional cast iron cylinder liners, the
bores now treated to the Yamaha-
patented electro-deposited low-
friction ceramic coating. Even the
layout for the oil filter and cooler
was redesigned, sitting side-
by-side at the front of the block
rather than being stacked, as per
conventional thinking. This gave
Miwa-san the ability to mount the
headers of the four-into-one ex-
haust system—featuring a revised
version of the EXUP (Exhaust Ulti-
mate Powervalve) system—closer
Yamaha was a die-
hard believer in the
five-valve cylinder-
head, only going to a
four-valve in 2007.
