A Tyre For All Seasons

Atlas F1

A Tyre For All Seasons

by Tom Keeble, England

Recently, there has been a lot of debate in the F1 circus on the expected move to tyres for both wet and dry conditions in 2001. Ostensibly, the reasoning behind this move includes:

  • reduced costs for manufacturers;
  • reduced development time required for teams;
  • reduced running speeds in dry conditions;
  • much reduced running speeds in wet conditions;
  • more obvious application to road cars.
The tyres would obviously have to be a compromise between wet and dry ideals. Currently, cars running in dry conditions use relatively hard rubber, which operates at an ideal temperature in the region of 80 degrees upwards; full wet tyres are made from a softer compound, and as they are exposed to cold standing water must be optimised to work at under 40 degrees. As a current wet tyre is exposed to dry conditions, it rapidly overheats and goes off.

Tyres, tyres and more tyresLooking at a wet/dry combined tyre, the compromise becomes apparent. A tyre that is optimised for dry conditions is likely to have poor wet performance from the reduced running temperature and harder compound alone, whilst those optimised for wet conditions will certainly suffer from the increased temperature and wear in the dry.

Further, it is necessary to look at the amount of tread devoted to shifting water. A manufacturer who thinks the race weekend is certain to be dry will produce a tyre with no tread (effectively slicks). This would perform better than the current dry tyres with grooves. Similarly, should it be possible to predict a wet weekend, wet optimised tyres will be required which (again) would have little or no speed reduction for the conditions. So in order to fulfill the mandate above, the FIA will need to restrict the amount of rubber actually in contact with the track, ensuring at least there is an upper limit in terms of percentage of the tyre surface that may make contact (effectively, ensuring grooves are present).

Then, we must consider the individual circuits. There is a different likelihood of wet weather for each circuit, so the tyres optimisation towards wet or dry running will be different for each race. This in turn means the manufacturers will be required to develop a selection of tyres rated from '80% likely to rain' (Spa, Monaco), to '10% likely to rain' (Spain, Australia). That is without considering how hard it rains (read depth of standing water resulting from rain), which may range from none to a few inches! Again, the manufacturer will be required to optimise against the expected level of standing water in the event of rain.

So we are in danger of moving from the current position - several wet tyres by conditions (intermediates through full wets), and two dry tyres (prime/option) - to a single wet dry range that has to accommodate expected odds on rain falling through and the expected depth of standing water it would produce. Potentially, that's a new tyre per circuit, or two if 'prime' and 'option' are to be run.

Things could get interesting here, too. In a race containing mixed wet and dry conditions, the ebb and flow between performance within a team might change as a 'prime' shod car, wearing tyres optimised for wetter conditions, gains an advantage over an 'option' shod car that expects a drier race. Further, a team might gamble that the race is to be dry and send one driver out on a pure dry tyre; if it rains, he'll probably slide out, but if not then even a Minardi would expect to make the podium if all the other teams are wearing tyres optimised for wet running! It will be interesting to see what Mr Prost can make of it...

Then again, the FIA would not be fulfilling its mandate on reduced cost if the tyre manufacturers had to make 16 different tyres in order to have one per track, so they will have to legislate there too.

The idea certainly has merits, but there will be an awful lot of head scratching going on for the FIA to cover even the issues mentioned here before it happens.

But if they really want to fulfill the mandate, then perhaps they should consider another amendment to the rules: ban pitstops. Making tyres that last a whole race, in cars that have to carry fuel for the whole race, will certainly slow speeds. The tyres will be even more applicable to road conditions, and the manufacturers will not have to supply multiple sets for the race (reducing their costs further). Anad as an added bonus - we might even see some on track passing!

Tom Keeble 1999 Atlas Formula One Journal.
Send comments to: f1rumors@yahoo.com Terms & Conditions
Tom Keeble is an unlikely combination of Software Consultant, Competition Latin and Ballroom dancer, rugby player and Formula One enthusiast. Attempting to stay on top of the Formula One news and information scene has led to taking on some of the administration and writing of The F1 Rumors Site.