Some questions about F1 tyre sizes and diameters back in the day

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Potto
Potto
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Joined: Fri May 31, 2019 2:03 am

Some questions about F1 tyre sizes and diameters back in the day

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Is there any place I can find information about the front and rear tyre sizes of F1 car throughout the years? Particularly the 1960's-1980's period and the width of the tyres. I was also wondering if anybody knows why during the 1970's the front tyres got so small in diameter?

roy928tt
roy928tt
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Joined: Tue Jul 11, 2017 11:55 am

Re: Some questions about F1 tyre sizes and diameters back in the day

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I completely agree, it is hard to find this information.

The rear tyre size of 370mm width X 660mm Diameter x 13 inch wheel diameter, 15" x 26" x 13" seems to have remained constant up till the introduction of the radially grooved tyres.

Small diameter front tyres were probably a simple aerodynamic consideration, one would presume there was no actual regulation specifying tyre size, remember Tyrrell's 6 wheeler used 10" diameter wheels...

I don't know why F1 didn't leave the 13" wheel behind long ago, the Porsche 917 was using a similar size 15" wheel in 1969. It is so much easier to fit bigger brakes in a bigger wheel.

The story of wheel and tyre evolution , I'm sure would be interesting.

Cheers Roy

Tommy Cookers
Tommy Cookers
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Joined: Fri Feb 17, 2012 3:55 pm

Re: Some questions about F1 tyre sizes and diameters back in the day

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when I last attempted to check ....
the Lotus 18 (1960 2.5 litre F1 car + F2 car + FJunior car) apparently had ....
front tyres of 4.625" section ie width (presumably in F1 not unique to Lotus)
rear tyres (straining memory here) maybe 5.5"

recent 18 FJunior users say 4.50 x 15 front and 5.25 x 15 rear
btw the Lotus Elite (115 mph road car) had 3.50 - presumably front and rear

this was where the 1961-1965 1.5 litre F1 started
but by late 1965 the US drag slick influenced tyre war had Brabham and Lotus teams up to 10" ? rear width
ie the first tyre revolution was in that period

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jjn9128
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Joined: Tue May 02, 2017 10:53 pm

Re: Some questions about F1 tyre sizes and diameters back in the day

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There's a tab up the top with a database of cars, while it's not complete but there's a load of information there. If you can find the wheel rim size then you should be able to find a corresponding tyre here:

60s all weather tyres

slick tyres

These are raced in FIA historic series so I assume they're period correct size-wise.

Rear tyres were 26" diameter x 18" wide from the early/mid 70s through to 1993. Front tyres were typically 20" diameter x 10" wide by the end of the 70's but from 1981 increased to 25" diameter which remained the same until 1998. In the 60s some teams were using 15" diameter wheel rims but pretty consistently teams used 13".

There was a lot of experimentation with tyres in F1 throughout the 70s (not always scientifically based, e.g. 6-wheelers), I think mainly to do with the cross-ply tyres they used until the early 80s(?) so with a smaller side-wall you get less slip angle so you get more positive turn-in!?
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

Potto
Potto
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Joined: Fri May 31, 2019 2:03 am

Re: Some questions about F1 tyre sizes and diameters back in the day

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https://www.ferrari.com/en-EN/formula1/312-t5

On this site they list tyre sizes. The Ferrari 312T5 has the tyres listed as

FRONT TYRES
23/59 x 13”
REAR TYRES
38/68 x 13”

I'm not sure what these represent aside from the rims.

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jjn9128
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Joined: Tue May 02, 2017 10:53 pm

Re: Some questions about F1 tyre sizes and diameters back in the day

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Potto wrote:
Wed Feb 26, 2020 6:31 pm
https://www.ferrari.com/en-EN/formula1/312-t5

On this site they list tyre sizes. The Ferrari 312T5 has the tyres listed as

FRONT TYRES
23/59 x 13”
REAR TYRES
38/68 x 13”

I'm not sure what these represent aside from the rims.
Those are in cm. 23cm tread with a 59cm (23") diameter on a 13" rim, 38cm tread with a 68cm (26"-27") diameter on a 13" rim. Don't know about rim widths, but I'd suggest the front would be ~7" and the rear between 16-18".
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

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strad
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Joined: Sat Jan 02, 2010 12:57 am

Re: Some questions about F1 tyre sizes and diameters back in the day

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Rim width is something the teams played with some time back.
At one point they decided to mount the tires on a too narrow (by typical wisdom)rim then thay decided to mount the tires on a too wide rim.
Personally I thought stretching the tire over a wide rim would be best...guess I was wrong or they would still be doing it. :wink:
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss

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JordanMugen
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Joined: Wed Oct 17, 2018 12:36 pm

Re: Some questions about F1 tyre sizes and diameters back in the day

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Here is a previous thread about the 1980's tyres:
viewtopic.php?t=27696

In 1975, the Goodyears were:
Front 20.0"x9.2"-13"
Rear 26.0"x16.2"-13"
https://www.f1technical.net/f1db/cars/335/ferrari-312t

The maximum rear tyre width was reduced in 1982, and from 1982 to 1992, the Goodyears were:
Front 25.0"x10.0"-13"
Rear 26.0"x15.0"-13"
https://www.f1technical.net/f1db/cars/6 ... i-f1-87-88
Potto wrote:
Sat Feb 22, 2020 10:09 pm
Is there any place I can find information about the front and rear tyre sizes of F1 car throughout the years? Particularly the 1960's-1980's period and the width of the tyres.
This may help:
Image
Image
https://www.stuckey.com.au/News-and-Inf ... Race-Tyres

The website doesn't list the tyre sizes, but if you go through the Dunlop historic racing tyre catalogue, you can cross-reference the tyre model to it's size, and associate that with when that model tyre was raced in F1. :)

Pingguest
Pingguest
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Joined: Sun Dec 28, 2008 3:31 pm

Re: Some questions about F1 tyre sizes and diameters back in the day

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The FIA's historic database might help. Until 1982, the Year Book of Automobile Sport included Formula One's technical regulations.
https://historicdb.fia.com/regulations/ ... appendix-j

Until the end the 1980 season, tires were allowed to be 21 inch wide. This was reduced to 18 inch from 1981.

CG901
CG901
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Joined: Sun Apr 12, 2020 4:42 pm

Re: Some questions about F1 tyre sizes and diameters back in the day

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I have 5 F1 cars all from 1988-1992. Wheels were 11.5" front and 16.5" rear. Goodyear fronts were 25.0x10.0-13 and rears 26.0x15.0-13. Trying to attach some images but not working.

gold333
gold333
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Joined: Mon May 16, 2011 1:59 am

Re: Some questions about F1 tyre sizes and diameters back in the day

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I believe that may require a bit of additional explanation. Historic F1 cars in private hands today are usually shod on Avon tires which replicate the old Goodyear/Pirelli tires. The Avon tires are known to have a much more forgiving slip angle than the original competition tires though, they are also not always exactly the same dimensions as the originals.

Which cars do you have and what tires are the cars currently using?

https://en.wikipedia.org/wiki/Formula_One_tyres

Until 1992 rear tire width was 18 inches (45 cm). Today it is 15.9 inches (40.5 cm).
F1 car width now 2.0m (same as 1993-1997). Lets go crazy and bring the 2.2m cars back (<1992).