Although it was resurfaced only four years ago, the Rio de Janeiro circuit doesn't have a reputation for offering the traction one would hope for while racing a 240-plus horsepower machine...

In fact a combination of many bumps, low grip levels and minimal camber on the medium to high-speed corners make this a very challenging circuit. Since there's only one extremely hard braking corner, most of the rider's attention will be focused on manoeuvrability, but more importantly drive. Past experience has shown this is the key area for success.

This is one of the M1's strengths, but the issue for Yamaha in the past has been its somewhat flighty nature, which easily became unsettling and reduced rider confidence on the type of bumps found at circuits such as that used for the Rio MotoGP.

For 2004 Yamaha his confident that this has now been resolved - evident with Rossi's Welkom performance, which is another circuit infested with bumps. It's the result of the M1's 2004 chassis, with its reduced lateral rigidity, which has improved feel at high lean angles. Also supported by the revised power delivery of the 2004 engine, which when combined with the 2004 chassis, offers the rider the confidence to drive hard off any manner of corner exits.

Agility is achieved by preventing the rear from squatting under power by using more preload on a softer rate rear spring. This combination holds he shock high in its stroke, ensuring the bike is able to turn efficiently, while the softer spring offers better feel and drive.

Combined with less rebound damping - to allow the shock to return to its static length before the next series of bumps - feel is improved and, therefore, control under power without sacrificing the positive handling traits initially sought after.

Again the front-end will follow the same basic theme as the rear to ensure an overall neutral balance, and with minimal hard braking it will allow more effort to be directed towards improving feel. As Rio is an acceleration circuit the power characteristics will be concentrated towards the midrange and top-end.



Loading Comments...