Tire to rim ratio

[riff_raff]

I haven't seen an F1 tire up close in the last 7 or 8 years, but the last ones I handled were incredibly light. I'm sure the (used) rear I saw was easily less than 20 lbs. In fact, the thing that was most impressive about the tire, was how thin the sidewall was. It seemed as though you could put your finger right through it.

The tread rubber (at least what was left of it) was also so soft that you could scrape chunks of it out of the tread surface with your fingernails. The sidewalls and tread carcass of F1 tires are so thin and light, it's easy to see why they get punctures from running over any debris on the race track.

While F1 tires may seem like the single most high performance application there is, I personally think NASCAR tires are worked harder. Not only are NASCAR tires smaller, they must also have inner liners and they are subjected to much heavier cornering loads. Due to Cup cars being twice as heavy as an F1 car and running at consistently higher cornering speeds.

Of course, f1 tire dimensions (rim diameters and tread widths) are limited by rules.

[Belatti]

If you pay attention to the ease the pit mechanics lift up F1 tires in pitstops, you can guess they are really really light

[Nealio]

Formula 1 tires are designed to maximize tire lateral force, longitudinal power transmission and overall traction on dry, high grip flat and very smooth track surfaces. A higher aspect ratio provides a larger contact patch and is the best compromise to achieving the traction goals under the technical regulations of F1 (you don't want to hear it but it's true). A formula 1 tire is actually very light. The tire construction is surprisingly thin and the tire/wheel package lighter than a large (18 inches plus) package of the same dimension would be. Even titanium is not as light as air!
Another salient point concerns heat. A low aspect tire by design has a much shorter sidewall. In flexation this area creates more friction than a taller sidewall which leads to higher and faster heat gains (plus heat retention because of the heavier construction of the sidewall in low-aspect tires) resulting in the earlier failure of the tire.

[riff_raff]

The max diameters of the tires (660mm for drys and 670mm for wets) and wheels (332mm max bead diameter, or basically 13 inch wheels), as well as details like area and location of tire contact patches, are tightly controlled by the FIA.

The best traction will always result from a good contact patch. Which in turn is best with the largest diameter and widest tire that can reasonably be used. F1 cars have small 13 inch wheels with the largest diameter tire rules allow. This results in the tall sidewalls you see on an F1 tire. This is due entirely to the rules. Sports cars don't have the same wheel diameter limits, so they use larger diameter wheels and lower aspect ratio tires, which are technically a better choice.



Regards,
Terry

[Pandamasque]

This is due entirely to the rules. Sports cars don't have the same wheel diameter limits, so they use larger diameter wheels and lower aspect ratio tires, which are technically a better choice.

Could this have an effect on overtaking? Sportscars seem to be more controllable off the line (and generally in hairy situations).

[autogyro]

This is due entirely to the rules. Sports cars don't have the same wheel diameter limits, so they use larger diameter wheels and lower aspect ratio tires, which are technically a better choice.

Could this have an effect on overtaking? Sportscars seem to be more controllable off the line (and generally in hairy situations).

A very good point.
I for one would like to read more on F1 tyres and the reasons behind 13 inch rims.
Is it just a throw back to old times when 13inch rims were the standard on most things and it has become locked into the regulation mix?
Or are there real reasons for the size limit.

[DaveW]

FWIW, the unsprung mass & tyre vertical stiffness of a P2 vehicle are both roughly double those of an F1 vehicle.

F1 vehicles tend to rely on aero for CPL control, with little reliance on mechanical control. Reduce or remove the D/F & CPL control is often negligible....

[Jersey Tom]

Could this have an effect on overtaking?

Nah. Consider how much overtaking there is in NASCAR, and they have huge tall sidewalls just as much.

[Pandamasque]

Could this have an effect on overtaking?

Nah. Consider how much overtaking there is in NASCAR, and they have huge tall sidewalls just as much.

'Stock' cars don't seem like a good comparison. Cars are very different and move around a lot, very heavy, with huge brake distance.

[Jersey Tom]

I don't think tall sidewalls have anything to do with it regardless.

[ackzsel]

I'm not much of a photo shopper but this time I couldn't resist
Quick and dirty but it's evident that bigger rims will have a huge impact on the aesthetics of the car.

[mcjamweasel]

I like that actually.

[autogyro]

I'm not much of a photo shopper but this time I couldn't resist
Quick and dirty but it's evident that bigger rims will have a huge impact on the aesthetics of the car.

Great, bring back mechanical handling and reduce DF by as much as possible and we could have decent F1 racing once again.

[alelanza]

Could this have an effect on overtaking?

Nah. Consider how much overtaking there is in NASCAR, and they have huge tall sidewalls just as much.

Emmm... in NASCAR you don't overtake by outbraking other cars into a corner. That's not to say the don't brake, they sure do heavy braking on most tracks. That being said i don't think it would change overtaking too much either. On the other hand having watched the aussie v8s in yas marina, it's true they were a lot more comfortable offline, but then again there are so many differences it's hard to pin it down to just tyre wall size.

[Jersey Tom]

Emmm... in NASCAR you don't overtake by outbraking other cars into a corner.

Yes you do. Best example of it will be this coming race.