Grand Prix 2001 - Round 14 - Phillip Island set-up report

Grand Prix 2001 - Round 14 - Phillip Island set-up report
By Yamaha

Circuit: Phillip Island
Date: October 14, 2001
Track length: 4445 m
Opened: 1956
500 GP lap record: Kenny Roberts (Suzuki) - 1'32.743, 172.654 km/h (1999)
500 GP circuit best lap: Kenny Roberts (Suzuki) - 1'32.319, 173.450 km/h (1999)
500 GP 2000 race winner: Max Biaggi (Yamaha)

The fast flowing nature of Phillip Island is a favourite of many riders, often lending itself to close racing, while allowing the rider the rare opportunity to be truly aggressive on the 180 horsepower 500. Efforts will be targeted towards good acceleration and turning ability rather than braking stability - a given considering there’s only one excessive braking area, Qantas Corner. The Island, as it is often referred to, offers a variety of cambers throughout its sweeping corners; both positive and negative. Therefore the key component to success will be the rear suspension unit. It will need to offer a plush enough ride to ensure good predictable traction without pumping through its stroke as the rider tries to drive hard off the side of the tyre, or squatting as the weight transfers onto the rear. The latter would only unload the front of the motorcycle causing it to run wide - affecting exit speed and laptimes. On the other hand a too stiff a rear shock will only lead to the 500 lofting the front wheel off each turn.

To achieve all that is needed of the rear shock it will need to sport a slightly softer spring rate to aid feel, with a reasonable amount of preload to prevent rear end squat. As for the damping it will help balance out the package. The front forks will mimic the rear setup to ensure a overall balanced geometry. Too hard and the front will become vague in its feedback, too soft and the basic feel will be too loose to be efficient.

As is often the case when drive is important the Yamaha riders are more likely to opt for a longer swingarm to offer predictability and stability under power while reducing the likelihood of the bike wheel standing.

Power is tuned more towards offering a strong midrange to top end with acceleration the key to a fast lap time, especially off the final fast turn where momentum can make the difference between winning and losing - just ask Olivier Jacque and Shinya Nakano, the Frenchman taking the MotoGP250 World Championship title in the final few meters.

Tyre choice is also crucial here, but also difficult to get right. With the temperamental weather the track temperatures can vary greatly and in turn so can the ideal tyre choice. Tyre technicians also need to take into consideration the long periods that are spent driving hard off the left side of the tyre - which is why the 16.5inch slick is the only choice. The challenge is to offer the grip and longevity on the left side, dealing with the massive heat build up, while also generating heat and grip on the less used right side. To do this Michelin has produced dual compound tyres in the past that are harder on the left and softer on the right. These are likely to make an appearance again in 2001.