59 replies to this topic

[sanW10]

Why do we have such fat tires in F1 & other formula categories?
I've never thought of this, but saw this question asked in Reddit F1
http://www.reddit.com/r/formula1/

Edited by sanW10, 26 March 2013 - 13:49.

[akshay380]

I dont know the reasons but Indy too has low profile tires?

[Ross Stonefeld]

I wouldn't say Indy is a low profile tire. Certainly not sportscar/gt/touring car low.

[d246]

Good question. Can't figure out what the answer is though.

[Ze Bum]

In the 90s the FIA said they wanted to keep the 13 inch rims so that the brakes wouldn't be to big and powerful. So to keep the cars slower.

[muramasa]

more like tradition I believe.

same as open cockpit and open wheel.

[Amphicar]

There is no technical reason for Formula 1 persisting with 13" wheels and high-profile tyres - it is resistance by the teams that has stopped the change being made. In 2010 after Bridgestone announced that it would pull out at the end of the season, Michelin made a proposal to supply tyres. Part of the bid was a change to 18" rims. Initially Michelin wanted to make the switch immediately (i.e. in 2011) but they later said they were willing to delay until the new engine formula came in (at that time, planned for 2013).

The teams were opposed to 18" wheels because it would require redesigning the suspension of their cars, which currently rely on the tyre sidewalls for much of the overall compliance in the suspension. So one of the reasons we now have Pirelli (apart from the fact that they were cheaper) is that they were willing to continue with the 13" wheels, while Michelin weren't.

[MP422]

Like said above, the cars use the tires sidewall in conjunction with the suspension. 18" wheels would look quite silly.

Edited by MP422, 26 March 2013 - 18:11.

[Ze Bum]

Like said above, the cars use the tires sidewall in conjunction with the suspension. 18" wheels would look quite silly.

I'd say they would look more normal now. The 13 inch wheels and fat tyres look very old fashioned.

One would think that the teams would like to design their own suspension with real suspension parts. Not use some unpredictable tyres as part of it.

[sanW10]

hmm
does FIA say anything about tires specs?

sorry, forgot to link to Reddit thread.
http://www.reddit.co...that_i_couldnt/

[Amphicar]

hmm
does FIA say anything about tires specs?

sorry, forgot to link to Reddit thread.
http://www.reddit.co...that_i_couldnt/

Yes but it is more the wheel specification that is relevant. Article 12.4.4 of the FIA 2013 Technical Regulations states:

Wheel dimensions and geometry must comply with the following specifications :
- The minimum wheel thickness is 3.0mm.
- The minimum bead thickness is 4.0mm (measured from hump to outer edge of the lip).
- The ETRTO standard bead profile is prescribed.
- The tyre mounting widths are 12” (304.8mm +/-0.5mm) front; 13.7” (348.0mm +/-0.5mm) rear.
- The wheel lip thickness is 9mm (+/-1mm).
- The outer lip diameter is 358mm (+/-1mm).
- A lip recess of maximum 1.0mm depth between a radius of 165mm and a radius of 173mm from wheel axis is permitted (for wheel branding, logo, part number, etc).
- With the exception of the wheel lip, only a single turned profile with a maximum thickness of 8mm is allowed radially outboard of the exclusion zones specified in Article 12.4.5.
- The design of the wheel must meet the general requirements of the tyre supplier for the mounting and dismounting of tyres including allowance for sensors and valves.
- The wheel design cannot be handed between left and right designs.

[trogggy]

Like said above, the cars use the tires sidewall in conjunction with the suspension. 18" wheels would look quite silly.

Judge for yourself...from an old thread on the subject:

Old post from 2010 showing different tires on a Ferrari:


Current 13-inch


15-inch


Champcar 15-inch (27 vs. 26 diameter rear tire)


Proposed 18-inch

[pingu666]

well with low profile tyres your suspension would need a greater range of movement

[One]

low profile will run the track quicker. it has then a larger brake disk, which was not what max wanted.

[trogggy]

low profile will run the track quicker. it has then a larger brake disk, which was not what max wanted.

Why?
There's the potential to fit a bigger disc, obviously, but only if the rules say so.

[pingu666]

you might get more control with low profile too, as tyres act as springs without dampers, oh and a fairly random rate too, big sample varience. some supliers do try to rate and match tyres based on spring rate from some tests

[britishtrident]

Smaller brakes extend the braking zone to encourage overtaking

Of course looking at it from the endurance racing side overtaking under braking isn't important and they need the biggest brakes possible for Le Mans

Edited by britishtrident, 26 March 2013 - 20:55.

[Kalmake]

"Small wheels because they want to use tyres as suspension" would a good addition to the F1 myths thread (if it wasn't in shambles).

[Victor_RO]

Smaller brakes extend the braking zone to encourage overtaking

Of course looking at it from the endurance racing side overtaking under braking isn't important and they need the biggest brakes possible for Le Mans

Biggest brakes with the maximum possible amount of cooling in order to go the full 24 hours on a single set of discs and pads.

[Kalmake]

F1 brake discs being small to increase braking distance is another myth. Indy have/had this, not F1.

Having smaller wheels to limit brake size is just nonsense, they could just measure the discs obviously.

[One]

Why?
There's the potential to fit a bigger disc, obviously, but only if the rules say so.

was discussed previously. Naturally with Aero impact you could specify smaller disk. But then I ask why? Just for the look of it? Where should a finesse of technology and engineering go?

[trogggy]

was discussed previously. Naturally with Aero impact you could specify smaller disk. But then I ask why? Just for the look of it? Where should a finesse of technology and engineering go?

Smaller brake discs 'for the look'?
What?

[Snic]

Simple answer :

Tyre manufacturers want more advertising space

[Ross Stonefeld]

At those speeds a blur is a blur.

[LostProphet]

The current tyre regs are ridiculous - just another part of F1 that has no relevance to modern day motoring.
Mostly it's been pressure from the teams.

Most, if not all, teams are now pretty well set with their vehicle dynamics. A large amount of the damping comes courtesy of the massive tyre sidewalls, and the cars have all been fettled around that.

Moving to bigger rims and lower profile tyres makes sense from every point of view, except for this one. Essentially the teams would be starting from almost zero with their suspension and vehicle dynamics designs and tests.

Dieter Rencken did a great article a while back on Autosport about this, essentially saying the same thing (albeit much more eloquently than I can).

I believe at one point, the 2014 regs (back when they were 2013 regs and had an Inline-4 engine involved) involvedd 18" tyres but I think that's been dropped. Again.

Maybe one day!

[Ross Stonefeld]

Of all the things you people light torches over, wheel rim diameter is the silliest.

[LostProphet]

Of all the things you people light torches over, wheel rim diameter is the silliest.

I just think it's daft that, in a world where cutting edge isn't quite cutting edge enough, an area is being neglected.

Even moreso now with the push for 'road relevant' technology. With fuel efficiency being key, surely being able to develop tyres that give great grip with great fuel efficiency is good for the teams, and the tech will filter directly back to the road car side of things?

Just don't put them on Run Flats

[bobqzzi]

13" wheels/tires are much lighter

[EthanM]

I just think it's daft that, in a world where cutting edge isn't quite cutting edge enough, an area is being neglected.

Even moreso now with the push for 'road relevant' technology. With fuel efficiency being key, surely being able to develop tyres that give great grip with great fuel efficiency is good for the teams, and the tech will filter directly back to the road car side of things?

Just don't put them on Run Flats

it's not as simple as that, put a skinny tyre on an f1 car, run a couple of racing laps in Suzuka you will have a tyre failure in 130R.

[ViMaMo]

15 inch looks decent, 18 inch looks average.

[Aubwi]

I think the lower profile tires look a bit junior formula. Reminds me of Formula Mazda or something.

[Tenmantaylor]

18s look silly on an F1 car, like a 17 year old maxed it and dropped it without knowing about car setup. If the profile is too low the suspension will need quite al ot of extra travel and be softer. I agree the teams could control this better with suspension but the sidewalls help generate heat in the tyre also and protect the rims from kerb impacts etc. Low profile isn't guaranteed to be faster/better. If the teams could xhoose on a race by race basis id imagine low profile would be desirable at flat smooth tracks and higher profile desirable at bumpy Street circuits where kerb riding is needed.

Edited by Tenmantaylor, 27 March 2013 - 07:26.

[Felix]

2008:


http://www.autosport...le.php/id/1642/

[V8 Fireworks]

Good question. Can't figure out what the answer is though.

It's just the regulations about maximum rim size. That's all.

Obviously a quick comparison of the material around the rim will show that a smaller wheel is much lighter, and I guess F1 teams are reluctant to build more suspension travel into their designs for a 15" tyre.

Edited by V8 Fireworks, 27 March 2013 - 08:48.

[V8 Fireworks]

Low profile isn't guaranteed to be faster/better.

Nobody told Chrysler or General Motors

Who says a muscle car shouldn't have a ride quality to make any pregnant occupants feel physically ill on 20" rims and painted on tyres...

Edited by V8 Fireworks, 27 March 2013 - 08:34.

[V8 Fireworks]

With fuel efficiency being key, surely being able to develop tyres that give great grip with great fuel efficiency is good for the teams,

An F1 car has what, say many times the drag of a closed wheel LMP1, and orders of magnitude more than a Prius. I just don't think that would make any difference, nor really make sense in a slick racing tyre. =)

The KERS and turbos are on that path of efficiency for sure. I think a 3.5L V12 regulation would be more entertaining though...

[Amphicar]

13" wheels/tires are much lighter

But the tyres are much heavier - more rubber in the carcass - and I reckon overall a 13" wheel and tyre would be significantly heavier than an 18" wheel with a low-profile tyre.

[KnucklesAgain]

"Small wheels because they want to use tyres as suspension" would a good addition to the F1 myths thread (if it wasn't in shambles).

Not a myth at all. It's not about specifically *wanting* to use the tyres as suspension, but about having done so in the past. Changing now would mean to bin all the data and experience they have with current suspension design.

Autosport 2010

It is also understood that serious consideration is being giving to the French tyre company's desire to make F1's tyres bigger - by running 18-inch diameter tyres rather than the 13-inch ones that are currently used.

Such a move would force teams to make a major revamp to their car designs for 2011 – and it something that Gascoyne believes needs to be thought through with great care before the go-ahead is given.

"It will have a huge impact – and it depends on how we address it," Gascoyne told AUTOSPORT about the prospect of Michelin re-entering F1 next year with 18-inch tyres.

"Some people are saying let's not allow anyone to change anything on the suspension and put 18-inch rims on it, which you can sort of see why. But then you are going to have to change it at some stage and, if you are going to do so, why not do it straight away.

"It is something that I have mixed views about. In some respects as a new team you like big rule changes because it is a great leveller. In other ways, as a new team, maybe you don't have the number of people and the facilities to cope with it – but bring it on. Whatever it will be, we will get on and deal with it."

Gascoyne believes that as well as forcing teams to make big suspension changes, the change of tyre size will have other implications on car design.

"The aero implications are very big as well, it is huge. That is why I think we need to think carefully.

"Obviously there will also be less air in the tyres, so pressure management and all things like that become easier. There are less variables though.

"Obviously with the sidewall stiffness, a variable is taken away out of the suspension system, so there is a lot more space within the uprights – but do you then start damping the wheels and all sorts? We need to think quite carefully about it - that we don't end up allowing huge expense back into the sport."

He added: "Some of the big teams may not want it themselves because they will want to maintain the status quo, but there is a big aero change with the ban on double diffusers anyway – so teams will have to design new cars.

"But from my perspective, every time there is a rule change we are not having to catch up with the two or three year's development we are behind, so we look forward to a big rule change. We will get on and deal with whatever it is."

Bridgestone's director of tyre development Hirohide Hamashima believes a move to 18-inch tyres will lead to a big change in car handling.

"Generally speaking, if we put 18-inch tyres on the current cars suddenly, then it will have big oversteer – and will have less traction very quickly," he told AUTOSPORT. "Teams would have to redesign the rear suspension, aerodynamics and brake discs. It would be a lot of money and a lot of work."

Gascoyne is also wary about the prospect of a new tyre war in F1 – with the FIA having favoured a standard tyre for the last few years in a bid to bring down costs.

"I think tyre wars, with limited testing, will be hard," said Gascoyne. "Tyre wars are great if you are on the right tyre, but pretty bad if you are on the wrong one. And again, tyre wars have never brought down costs, they only make them spiral upwards. So again I think we have to be careful about that."

[EthanM]

Nobody told Chrysler or General Motors

Who says a muscle car shouldn't have a ride quality to make any pregnant occupants feel physically ill on 20" rims and painted on tyres...

Muscle cars don't corner at 5g. A skinny tyre on an F1 car runs the very real risk of ripping the tread off without the sidewall flexing to cushion the loads. There were some superslowmo shots in the last race actually that demonstrated that.

Video conveys this much much better than a still image ever could but ... focus on the rear right tyre

[One]

Smaller brake discs 'for the look'?
What?

no, lower profile tire is the theme of this thread. Apparently I am asking the reason as to why should a pinnacle of car racing choose to employee a low profile tire with no specific reason to make car run quicker.

[V8 Fireworks]

Of all the things you people light torches over, wheel rim diameter is the silliest.

Well the Ferrari F138 has the same wheel size as a Fiat 500. Does it make sense?

At least the wheel is somewhat wider... although maybe Tony will always look cooler in his fully sick Abarth

[One]

I just think it's daft that, in a world where cutting edge isn't quite cutting edge enough, an area is being neglected.

Even moreso now with the push for 'road relevant' technology. With fuel efficiency being key, surely being able to develop tyres that give great grip with great fuel efficiency is good for the teams, and the tech will filter directly back to the road car side of things?

Just don't put them on Run Flats

this lecture is to me a little bit obsolete, tho in principle agree with...

why not then a wing car? it will make the race car go faster.
why not a turbine engine?
why not free engine format?
why not a q-car?
why not a spare chassis at race week ends?
why should pirelli coome up with tire that falls apart quicker than any road car?
why not traction control?
why not GPRS ?
why not two way telemetry?
why not programmable suspension system?
why not active ride heights control system?
...

cieling must be set from driver racing with jet fighter suits, and protect them and audience from fatality...

[FPV GTHO]

Muscle cars don't corner at 5g. A skinny tyre on an F1 car runs the very real risk of ripping the tread off without the sidewall flexing to cushion the loads. There were some superslowmo shots in the last race actually that demonstrated that.

Video conveys this much much better than a still image ever could but ... focus on the rear right tyre

^^Situation like that will likely just result in a lateral slide.

It was said in 2010 when this was last talked about seriously that the low profile tyres would probably have less grip than the current ones, albeit with more control over the suspension and more response.

Edited by FPV GTHO, 27 March 2013 - 11:33.

[V8 Fireworks]

why not a turbine engine?

The power delivery sucked (no, not literally) didn't it? Just not progressive enough for use on road courses.

I'm sure VW are always thinking of ways to make their economy cars more complicated (so Joe Bloggs needs a super and turbocharged engine and a 7 speed semi-automatic gearbox to go buy some bread and milk, really?), so I wouldn't put it past them on having a turbine powered Polo in their R&D department!

Edited by V8 Fireworks, 27 March 2013 - 11:36.

[One]

The power delivery sucked (no, not literally) didn't it? Just not progressive enough for use on road courses.

I'm sure VW are always thinking of ways to make their economy cars more complicated (so Joe Bloggs needs a super and turbocharged engine and a 7 speed semi-automatic gearbox to go buy some bread and milk, really?), so I wouldn't put it past them on having a turbine powered Polo in their R&D department!

apparently i forgot to name bernie's sucker car!

[Amphicar]

Muscle cars don't corner at 5g. A skinny tyre on an F1 car runs the very real risk of ripping the tread off without the sidewall flexing to cushion the loads. There were some superslowmo shots in the last race actually that demonstrated that.

Video conveys this much much better than a still image ever could but ... focus on the rear right tyre

But that has nothing to do with the retention of 13" wheels in F1. As already pointed out, Michelin were completely confident that they could produce a low profile F1 tyre for an 18" wheel. Currently, F1 tyres run with very low pressures, which contributes to the flexing of the sidewalls and to the tyres' de facto role as part of the suspension. A low-profile F1 tyre would run at higher pressure.

[FredrikB]

A low profile tyre would throw years and years of data and experience more or less out of the window since it would completely change the dynamics of the wheels/suspension/chassis. Even the Aero would be different.

Teams don't want that.

[Kalmake]

Michelin 18" = 46cm would have still left 20cm for tyre. So it wouldn't have been as low profile as "relevant" sports cars feature


but it would have been a step away from Donald Duck

[ensign14]

They need to be fat enough to get the logo on them.

[One]

mode nothing but a mode. looks is not a factor for engineering.

on turbine, acbc stopped as its turbo lag was terrible. but it is almost 44 years ago.