Actual size of Goodyear F1 tyres & wheel rims used 1989-1992?

[JordanMugen]

Sorry to bother...

I note the earlier Ferrari F1-87 is listed as using a Goodyear 25-10.0-13" [overall diameter - width - rim diameter] in the front and a Goodyear 26.0-15.0-13" in the rear. While the smilar era Arrows A10 is said to use a 13x12" front wheel and a 13"x16" rear wheel.
https://www.f1technical.net/f1db/cars/6 ... i-f1-87-88 https://www.f1technical.net/f1db/cars/588/arrows-a10

That rear tyre size & rear rim size seems too narrow, compared to reports of teams using an 18" wide rear rim width in 1992 before it was narrowed to 15" wide in 1993. Did the rear tyres and rear wheels get wider between 87 and 92? The front tyre size also seems too narrow compared to reports of teams using a 13x12" front wheel. You'd think a 10" wide front tyre would be better suited to a 13x11" front wheel.

The size of the Avon historic F1 slicks offered for sale don't match the Goodyears, in the front or rear -- which seems strange? The front historic Avons are a 23.0-10.5-13" [overall diameter - width - rim diameter] while the rear Avons are a 26.0-16.2-13".
The fronts are a much smaller overall diameter; it seems well established the Goodyear F1 front tyres were definitely 25" in overall diameter (as opposed to 26" overall diameter in modern F1 cars), so why are Avon only making a 23" overall diameter F1 front tyre available? http://www.avonmotorsport.com/historic/ ... ric-slicks

Avon suggests a nominal 13x11" rim in the front and nominal 13x17" rim in the rear. Narrower in the front and wider in the rear than what the Arrows A10 is listed as using!?

I was wondering if anyone knew the actual size of the Goodyear slicks and the actual size of rim the teams ran in 1989 through 1992 seasons?

Were 13x10, 13x11 or 13x12" rims used up front? Was it a 13x16, 13x17 or 13x18" rim out back? Or did various teams use different width rims depending on their unique ideology? Did all the teams use the same size slicks & rims, or were teams able to choose to use narrower slicks from Goodyear & narrower rims for aerodynamic benefits (e.g., if they had lower power V8 engines)?

If anyone had a high-resolution picture of the white decal (i.e., 92 and earlier) Goodyear F1 slicks, where the tyre size imprint is visible that would be really handy!



How come it's so hard to work out what rim and tyre sizes are on this and similar iconic F1 cars!

[OO7]

Hi Jordan

Unfortunately I don't have any information on the specifics of your questions, however regarding wheel widths, the rim widths are pretty much invariably smaller than the tyre widths. So while the rims may be 16" or so wide, the tyres when fitted and inflated to operating pressures or thereabouts, will be 18" wide and that's why their sidewalls bulge outwards slightly, either side of the rim.

Tyre bulge:

[roy928tt]

I'm afraid I can't definitively answer anything and I totally agree it is hard to find information from that period.

I have the rear end of a EuroBrun ER188. In sourcing wheels for it I ended up with a Pr. from an Ensign ( so earlier again) they are 16 1/2 inches wide. I believed that the tyre size stayed the same for an extended period, say, early 70's till the grooved slick era, for the rear that was 15/26-13 or 370/660-13.

Of course, matching wheels to hubs wasn't quite so simple......the ER188 being Italian built drive studs were 6 X 95 mm PCD and 16mm diam. the wheels were 6 X 3 3/4" and 5/8" diam. a difference of around .010" or .25mm some relieving of the wheels was required!

I don't believe F1 ever used 18" wide tyres. The total rear width did change several times with a maximum of 2.150 m around the late 80's, with the Ensign wheels my car measures 2.160, not quite optimum for it's use as a hillclimb car.

Cheers Roy

[JordanMugen]

Goodyear 25-10.0-13" [overall diameter - width - rim diameter] in the front and a Goodyear 26.0-15.0-13" in the rear.

It seems these sizes were correct for the yellow sidewall Goodyear, and for demonstration/historic events with 1980's and early 90's F1 cars, teams use metric radial Avon tyres (rather than the crossply Avons which are denoted by imperial sizes) in the sizes:
Front 245/640R13 [close to the Goodyear 25"-10" 13"]
Rear 370/660R13 [close to the Goodyear 26"-15" 13"]

Smaller than you would expect!

No wonder the current F1 cars with their 305mm wide front tyres look a bit ridiculous. F2 still uses the pre-2017 F1 Pirellis in the sizes front 245/660-R13 and rear 325/660-R13.

I guess the 245mm / 10" wide front tyre is a long-lived legacy rule^! While the 325mm rear of F2 must correspond to the narrower rear tyres (with maximum 15 inch section width) introduced in 1993. Avon sell a 315/660R13 radial rear tyre for use on post-1992 F1 cars.

For reference, 2017 onwards F1 cars use front 305/670-R13 and rear 405/670-R13 (the overall diameter having been bumped up by 10mm in 2017). The modern day rears are notionally wider than the fondly remembered fat rear tyres of the 1980's, though it does depend on the exact tyre shape.

^ Albeit during the grooved tyre era, front tyre were limited to maximum section (not tread) width of 355mm (14 inches) while rears remained limited to a maximum 15 inches section width.

[OO7]

It seems these sizes were correct for the yellow sidewall Goodyear, and for demonstration/historic events with 1980's and early 90's F1 cars, teams use metric radial Avon tyres (rather than the crossply Avons which are denoted by imperial sizes) in the sizes:
Front 245/640R13 [close to the Goodyear 25"-10" 13"]
Rear 370/660R13 [close to the Goodyear 26"-15" 13"]

Smaller than you would expect!

No wonder the current F1 cars with their 305mm wide front tyres look a bit ridiculous. F2 still uses the pre-2017 F1 Pirellis in the sizes front 245/660-R13 and rear 325/660-R13.

I guess the 245mm / 10" wide front tyre is a long-lived legacy rule^! While the 325mm rear of F2 must correspond to the narrower rear tyres (with maximum 15 inch section width) introduced in 1993. Avon sell a 315/660R13 radial rear tyre for use on post-1992 F1 cars.

For reference, 2017 onwards F1 cars use front 305/670-R13 and rear 405/670-R13 (the overall diameter having been bumped up by 10mm in 2017). The modern day rears are notionally wider than the fondly remembered fat rear tyres of the 1980's, though it does depend on the exact tyre shape.

Those dimensions are for tread width, so it's possible that overall tyre width (Goodyear vs Pirelli) is very similar or near identical, albeit with the former having more side wall bulge and less tread width.