Graining
Grain or grain is a result of overloading racing tires . The tire rubber, especially with slick , can no longer maintain its structure due to drive and / or cornering forces and “peel” itself. The resulting scraps of rubber clump together and stick to the tread of the tire. The graining reduces the tire contact area and thus changes the surface temperature of the tire. The temperature of the tire is decisive for the grip level.
Front tires are predominantly affected by graining, and this increases the understeering of the racing car. A dirty track surface also causes graining on racing tires because the tires “cannot grip the asphalt properly”.
Graining should not be confused with "pickup". Graining is a structural change made to one's own rubber, while a pickup is the conscious collection of external rubber (after the race is over). This is preferably next to the ideal line on the route. Low axle load and low speed make it easier to collect pickups.
The tire temperature is influenced by the setup in Formula 1 . Slight changes in downforce , camber or tire pressure ( flexing work ) also change the tire temperature. The optimal tire temperature for Formula 1 tires is between 80 and 100 degrees. If a tire falls below its operating temperature, it cannot develop any grip and slips. If a tire exceeds its optimum operating temperature, the “chemistry of the tire” changes; this leads to graining and loss of grip. For the four Formula 1 slick compounds from Bridgestone made available in the 2010 Formula 1 season , the optimum asphalt temperature was 25–40 degrees for the “supersoft / soft” compounds and 35–45 degrees for the “medium” compounds /hard".
“The tires are very sensitive, especially when they come out of the electric blankets. The surface temperature is then, but the inside has not yet warmed up [...] you may have grip on the first three or four corners, but then it can happen that the tire begins to pebble or degrade faster. I always try to get the tire up to temperature as gently as possible. [...] The best thing for the front tire is long waving movements at high speed. "
For the racing driver, graining feels like “driving on ball bearings”.
Individual evidence
- ↑ Hirohide Hamashima : Interview with the tire manager at Bridgestone . In: Formula 1 season 2010. Auto Motor und Sport. Page 49
- ↑ motorsport-total.com from July 19, 2004 Tire wear: what's behind it
- ↑ motorsport-total.com of October 22, 2010 Graining on both Bridgestone compounds
- ↑ Hirohide Hamashima: Interview with the tire manager at Bridgestone . In: Formula 1 season 2010. Auto Motor und Sport. Page 49
- ↑ Auto Motor und Sport Extra. Formula 1 review 2010: Interview with Sebastian Vettel. Page 20
- ↑ http://www.formula1.com/inside_f1/glossary.html formula1.com, glossary: graining