MotoGP
2005 - Round 12 - Motegi
Yamaha Set Up Report
September 13th,
2005
Round 12: Twin Ring Motegi,
Japan
Track length: 4801 m
Opened: 1997
Fastest Lap Ever: 1' 46.673 (Makato Tamada, 2004)
MotoGP lap record: 1' 48.524 (Makato Tamada, 2004)
Last year MotoGP winner: Makato Tamada
2004 race summary
Last year Valentino Rossi secured a second place result at the
Japanese Grand Prix at Motegi after a closely contested battle
with that weekends' fastest rider Makoto Tamada (Honda). Rossi
led the early stages of the 24-lap race but lost his advantage
to the Japanese rider from lap ten onwards. In front of a strong
crowd, Rossi made an excellent start from his front row grid
position, leading into the first corner and thus escaping a
six-rider pile-up that claimed Colin Edwards (Motegi was his
only race of the 2004 MotoGP season in which he failed to score
points). Rossi and Tamada charged away from the remains of the
pack, with the former leading until Tamada made a successful
pass along the back straight on lap ten. From that point on
Tamada built a gap over Rossi, and ended the race just over six
seconds ahead of the Italian.
Set-up report YZR-M1
Motegi is unsurpassed in its design and circuit quality - the
surface is seamlessly smooth, offering high levels of grip, and
the facilities are exceptional. Yet, despite this high attention
to technical detail the Motegi layout is far from being a
technically challenging circuit. The track can be characterized
as a series of 'drag strips', linked together by continual
radius second gear corners, a layout that isn't liked by many
and disliked by more. Even so it is still technically
challenging enough that outright power isn't the be-all and
end-all when it comes to winning races.
In fact in some respects too much aggressive power can be a
hindrance at this particular venue. As a result this should
prove to be of benefit to the 2005 YZR-M1, which beside shear
horsepower also has a very predictable powerband with an
excellent 'throttle linearity'. This performance trait is
essential since most of the +230 horsepower will be driven
through to the rear wheel on the exit of second and third gear
corners, only moments after completing some rather heavy
braking.
This combination of hard braking to hard acceleration
complicates things further with the aggressive weight transfer
being a catalyst for instability. For this reason a balanced and
usable base geometry will be the focus point for those riding
the M1.
The main aim in both instances (acceleration and braking) is to
cater for the aggressive weight transfer by minimizing the
pitching effect. To do this the basic chassis package won't be
too far removed from what was run during the Le Mans test
earlier in the year. The rear of the bike will be slightly lower
and the front set slightly higher, when compared to other
circuits, to offer the braking stability needed - reducing the
likelihood of the rear wheel leaving the tarmac. The front fork
springs will boast a slightly higher spring rate, but unlike Le
Mans, the damping won't have to cater for any real bumps during
the period the front forks are compressed.
The rear shock on the other hand will run a slightly softer
spring with a high amount of preload. This will help to offer
the feel and consistency under power while preventing the bike
from squatting to the point which can cause it to run wide or,
in extreme circumstances, wheelie. At the same time suspension
technicians will also have to consider the effects of the rear
shock pumping through its stroke - a common concern on a track
where the bike is driving hard off a slow speed hairpin.