With almost 7 years under their belt as sole supplier to the world’s premier motorcycle racing series, Bridgestone know a thing or two about race tyres.
MotoGP tyres are subjected to some of the most extreme forces in motorsport. A typical session will see a rear tyre stand up to some real punishment:
- Reaching operating temperatures of well over 100°C
- Dealing with loads of over 240kg
- Transferring over 250 horsepower to the tarmac, on a contact patch the side of a standard business card
It’s no mean feat developing rubber that can cope with all this and more, but it’s been a vital part of Bridgestone’s tyre development programme, providing engineers with plenty of valuable data which sees MotoGP technology transferred onto the road, in the form of tyres that you can buy for your bike as an everyday rider or racer.
But the story doesn’t end as soon as the MotoGP tyres leave the factory! There are many more aspects which need to be considered to ensure that riders and their teams can get the most out of the rubber.
Delivery
During the week prior to any Grand Prix, Bridgestone will transport hundreds of tyres to the MotoGP paddock. In Europe they have a fleet of five dedicated trucks based in Speyer, Germany. These transport around 1,200 tyres and all the equipment necessary to fit them correctly, plus offices for their high qualified engineers and team staff.
Outside of Europe, tyres are shipped directly to the circuit from Bridgestone’s factory at Kodaira, which is located near to Tokyo. The remaining equipment is packed into shipping containers supplied by the IRTA for delivery.
Allocation & Fitting
When they get to the circuit, Bridgestone staff will inspect each tyre, and mark the sidewall with a colour coded decal which allows teams and fans to easily see which compound the tyre is. These are then divided up into allocations for each rider, who has a set number of tyres available to them.
The tyres are randomly allocated to each rider by the FIM to ensure that there can be no accusations of bias. To enforce this, each tyre is marked with a unique barcode. At any point during the event the FIM can scan the barcode to check it is being used by the correct rider. If it isn’t, they will issue the team and rider with a penalty.
Teams bring their wheel rims to Bridgestone to be fitted with tyres from their rider’s allocation. On the day before the practice sessions begin, each rider will receive 10 rear slicks (4 harder compound, 6 softer compound) and 7 front slicks (3 each of the ‘prime’ compounds, 1 ‘alternative’ compound) as well as 5 sets of wet compound tyres. After Free Practice 2, a rider can select an additional rear tyre and 3 front tyres in their preferred compound.
To check that the tyre is sealed correctly on the rim, they are inflated to a very high pressure. Once this is confirmed, they are deflated to operational pressure levels. Bridgestone staff then check it for any irregularities, and although rare, if an imperfection is discovered it is replaced with an unallocated spare tyre once approved by an FIM official.
Final Preparation
Rider safety is always the top priority for Bridgestone, and as such all teams are provided with a working tyre pressure range to help optimise performance. As weather and track conditions change over the course of the weekend, Bridgestone will constantly update teams about the optimal pressures for each rider.
In order to ensure high levels of performance as soon as the bikes leave the garage, all teams store their tyres in heated blankets. These reach temperatures of around 80°C for slicks and around 60°C for wet tyres. Fitting the tyre to the bike takes around 90 seconds, and then the blanket is removed and the bike fired up.
When the bike comes back in to the garage, an engineer from Bridgestone will analyse the tyres to see how they performed out on track. They check both pressure and temperature to ensure that they are in a safe operating range, and a visual inspection confirms how the tyre in wearing on track. Any imperfections are then reported to the engineering team, who use this information to earmark further improvements which can be made for future events.
Over the course of a Grand Prix weekend, engineers will also carry out a more detailed analysis to check tyre wear and heat build-up. To do this they carry out a number of experiments and observations, which include cutting segments out of the tyres and then check them inside and out under a microscope.
Removal & Recycling
Once a tyre has reached the end of it’s usable life, it is returned to the Bridgestone fitting area where staff remove it from the wheel rim. The tyre can then be further analysed by engineers before being sent back to their warehouse in Germany, and placed into an energy recovery programme. Tyres used during the actual race are sent to Japan where they can be further analysed, identifying any strengths or weaknesses which will assist in tyre allocations for future races. This information is also used to further the development of Bridgestone’s publicly available race and road tyres.
For MotoGP on the road, it has to be Bridgestone – many developed, tested and approved by VR46 himself!
Check out their full range of motorcycle and scooter tyres here.
