Tyre tailoring keeps Weber a busy man

Michelin´s director of motorcycle racing Jean-Philippe Weber has a huge task on his hands in 2008, as the French tyre giant attempt to reclaim their status as the dominant force in MotoGP, in competition with Bridgestone.

The Japanese firm had the upper hand in 2007 but Weber and his staff redoubled their efforts over the winter to hit the ground running and have achieved two wins in four races thus far in the current campaign.

Tweaking the design of their tyres depending on the demands of the highly varied World Championship circuits and the specific needs of their individual riders, there are three main elements the tyre suppliers can alter, those being compound type, casing and shape.

As Weber explained in a recent chat with motogp.com in China, `It is quite a difficult process because we have to tailor-make the tyres from one track to another. The demands of the tracks depend on the amount of right or left corners and also depend on the nature of the asphalt, which may be more aggressive on the tyre. Then the tyre also has to match with the bike and the rider´s style in order to be as fast as possible.´

`We want to optimise the tyre in order to control the amount of wear. Here in Shanghai for example we don´t have so much wear on the tyres, because the track is not so aggressive.´

Going into detail on how tyre performance can be improved by changes to the production process, Weber focussed firstly on compound type - meaning the varying elements of rubber and synthetic materials within the tyre - commenting, `We know that a qualifying tyre is more or less a starting point for a fast tyre, so we have to give as much consistency as possible to the race tyre in order to be used over 20 or 22 laps. That means we have to use some harder compounds, but the compounds should still be as soft as possible.´

Moving on to cover the second of the three changeable elements of the competition rubber which can be changed according to requirements, Weber revealed, `We also have to manage the casing or the structure of the tyre, which has to vary in stiffness depending on the stress you put on the tyre. If you have a long time load on the tyres, if you have aggressive riders, you need harder casing. But the softer the casing is the better contact patch you get.´

Detailing the third tyre characteristic which can be altered, Weber noted the significance of the profile of the tyre, stating, `The shape of the tyre is very important because if you change the shape in order to give stability and traction you affect the wear of the tyre.´

`Of course, the profile is not changed as much as the compounds or the casing,´ added the Frenchman, `because each time you change the profile you have to use a different mold, so in terms of reactivity it is not as convenient to do as work on the compounds and the construction.´

Video subscribers can enjoy Weber´s interview in full. The video also features footage of an OnBoard lap with Michelin-equipped Tech 3 Yamaha rider James Toseland using a race tyre in free practice at Shanghai, in which tyre demand and deterioration can be closely observed.