Vyssion wrote: ↑22 May 2017, 12:00
Before that, the 1979 Alfa Romeo Tipo 17 used 635mm x 241mm R15 for the front and 737mm x 330mm R13 at the rear.
It seems Alan Jones and Neal Oatley are also talking about a choice 15" rear tyres in the 1981 film "Gentleman lift you skirts", so there were
both 15" fronts
and rears available up to the point that FIA mandated 13" tyres, so I don't understand where the notion of devotion to 13" tyres & high profile rubber came from, from some F1 fan quarters?
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.
1979: 635mm x 241mm R15
vs 2022: 725mm x 270mm(IIRC) R18
By any measure ( 635 mm - 15" ) / 2 =
127 mm sidewall in '79 and ( 725 mm - 18" ) / 2 =
134 mm sidewall in '22 are
very similar sidewalls.
Why a devotion to 13" tyres, when F1 cars historically used 15" low profile front tyres in the 1970's up to the point 13" was mandated?
For reference, the 1979 Alfa Romeo Alfasud Ti 1.5L hot hatchback was available with optional 16" wheels for maximum boy/girl racer bling! The Ti shod in 195/40 R16 would've been positively jaunty at the time, and had a similar 40% profile to the 225/40 R18 found on a modern 1.75L Alfa Romeo Giulietta Veloce.