Tyres play a huge role in motorcycle racing, the wrong choice can be a disaster for the rider - Michael Rutter at Cadwell Park last year anybody? Rutter ran full wets and then the track dried out, so it was game over for him.

Crash.net spoke Chris Valentine who is a Tyre Technician with Dunlop at the Cadwell Park BSB test. Chris is the first port of call for the riders, or their mechanics if they want to know what tyres to run, or if they have a problem with them. It is Chris' job to note which rider is running what tyre, and then check the tyre temperature when they come back into the pits.

Chris explains " The tyres have a window of 40?C that they work at. When the slicks come back into pits they should to be between 90?C and 130?C. Wets go up to 70?C." Getting the tyres to temperature is the team and the riders job, tyre warmers will take them up to approximately 80?C and the rest is up to the rider. The other factor that Chris looks at is the times the riders are doing on track on the tyre they are running, he gets these times direct from the team. That way he can see which tyre is giving them the best result and he can advise accordingly.

Track surface and temperature have a big effect on tyre performance too "The compound of the tyre is the part that is affected and as soon as a rider feels a change in grip the tyre will need to be looked at - it's not worn out, far from it, but it needs to be looked at. Track Temperature makes a big difference especially if cold, as it makes the surface harder," said Chris. Older tracks like Thruxton, which have a very rough surface and are very fast pose quite a challenge for all tyre manufacturers "The big problem we have there is the rubber overheating and the tyres melting, but it certainly helps us find the limits of our product."

"The most common problem we have is simply the rider not liking the tyre!" said Chris "It either won't have the level of grip that they wanted or they feel it is moving around too much for them." There is always talk about certain riders getting special treatment but Chris assures us that isn't the case, "We do focus on the top teams like GSE Ducati, Cresent Suzuki, Hawk Kawasaki and Karl Harris on the Honda, but we do make a point of trying to see everyone.The theory is, if they don't have a problem with the tyre then no one else should have."

Dunlop are currently supplying the bulk of the paddock with tyres which means on a race weekend they need three thousand tyres. To put that in perspective, it takes four of the Dunlop trucks to get them to the circuit. The usual break down of tyres is three front specifications, four rear specifications, and seven or eight of each spec will be available to the riders. They also need to supply qualifiers and wets which come in two different specifications. That is an awful lot of tyres!

At Cadwell, since it was a test day, Dunlop supplied John Reynolds with ten different front tyres to test and they had brought a total of fifteen hundred tyres with them. "On a race weekend we have similar tyres for everyone 300-400 of each spec," explained Chris "That is why we need four trucks per weekend."

The weather at Cadwell was mixed but apparently that isn't a big problem "Rain on a test day isn't a problem, we could do with a bit of both," said Chris "But it is up to the team, they might not run if it's wet, as they don't want to risk a crash."

As a qualified Design Engineer, when he isn't track side, it is Chris' role to put everything he has learned from a race weekend into the new tyre design. Computer software is used to simulate changes in the tyre during the design process and if Dunlop discover something vital at a test day or on a race weekend, the change can be implemented and fitted to a race bike within three weeks.