Just_a_fan wrote: ↑01 Mar 2021, 14:59
Tyres are provided by the nominated supplier. The tyre supplier doesn't want to make 13 inch tyres because they can't market them to boy/girl racers in their 2.0 litre hatchbacks.
They need to be at least 16" on my 2.0 litre hatchback to clear the brakes. I've got three sets:
16" (Mazda FD RX7)
17" (Mazda FD RX7)
18" (OEM Honda Civic Type R wheels)
Currently running the 17" wheels as they are nice lightweight forged wheels, as the 16" tyres had too much compliance in the sidewalls and made the handling a bit vague.
The 17" tyres seem to be OK as long as the tyre has reasonably stiff sidewalls like Potenzas. Pilot Sport 4 non-S were dreadfully floaty and had to be returned, and I worry that Eagle F1s would be nearly as bad (while I normally like Goodyear Eagle F1s, I've only driven them in 18" on the Civic or Megane, and unless you get the Eagle F1 Super Sport, they have a softer sidewall compared to Potenzas).
On the project car, a '93 Civic with the same 2.0 litre engine, it's running 15" wheels to clear 11" brakes, but they are fairly low-profile 15" tyres given the era of the car and the smaller overall tyres it runs compared to the later model Civic.
PS. I doubt the tyre suppliers have any issue making 13" tyres given they are still widely used in racing. Hankook were willing to make 13" on their F1 tender, Yokohama still make 13" for Super Formula, Kumho make 13" for F3000 type cars, as do Avon Cooper, Bridgestone were making 13" for Super Formula recently. Perhaps these suppliers simply didn't want to pay the outrageous fees demanded by Formula One Management!?
But ultimately when 18" tyres have been racing without issue for a
full season in Formula Two and they were demonstrably fine and of no issue, I don't understand how people can still be against the change.