As far as I know most people got the whole event out of 1 set of Dunlops, perhaps with the extra 2 tyres which were allowed. We had difficulty with different sizes front and back in complying but usually achieved it. When Dunlop change of staff had the company withdraw their very generous sponsorship the event went looking for someone else as a supplier, and Federal stepped up. From what inside info I was given at the time there was no other reason.