Does the FIA have a ruling on wheels?

[Sharky]

I was just wondering....but does the FIA have a ruling on the minimum moment of inertia of a wheel, it material and/or weight. I ask this because taking into account the ridicolous ammount of money that they spend nowadays on "details" to earn a couple of thousands of a second...I would expect the wheel manufacturers to develop new wheels made out of Titanium or beryllium alloys or perhaps even composite materials to reduce the moment of inertia of the wheels. So....does the FIA have any ruling that would keep teams from using any of these materials?

[Sparky]

FIA technical regulation says:

ARTICLE 12 : WHEELS AND TYRES

12.1 Location :

Wheels must be external to the bodywork in plan view, with the rear aerodynamic device removed.

12.2 Number of wheels :

The number of wheels is fixed at four.

12.3 Wheel material :

All wheels must be made from an homogeneous metallic material.

12.4 Wheel dimensions :

12.4.1)

Maximum complete rear wheel width : 380mm
Minimum complete front wheel width : 305mm
Maximum complete front wheel width : 355mm
Minimum complete rear wheel width : 365mm
Maximum complete wheel diameter : 660mm
Wheel bead diameter : 330mm (+/-2.5mm)

12.4.2) These measurements will be taken horizontally at axle height.

So, no minimum weight, and an 'homogenous metallic material' suggests no composites, but other than that, I think you're right. Teams could investigate alternative materials. I would think they already have, and have arrived at a compromise between weight and strength.

Anyone have any reason why not? I assumed they were just aluminium alloy.

[Sharky]

Mhhh....I see....however.....I've heard that there are some parts in an F1 car that are made of titanium....not an alloy but pure titanium....I would guess that you could make a wheel out of titanium and still comply with the rules....and since it's much stronger you could have less spokes (for instance) and therefore reduce the moment of inertia significantly....although...well...I'm checking my "engineering of materials" book....and well....it says that titanium (pure) costs about 28000 to 65000 dollars per kilo compared to the 11 dollars and 65 cents that you would have to pay for a 356-T6 aluminum alloy....so I think that it could proove to be too much money....even for high budget teams such as mclaren or ferrari.

[enzo]

I would expect that their wheels are magnesium, not aluminium, as the strength to weight ratio is more favorable, though forged titanium is also a distinct possibility. Titanium prices are very cheap, reletively speaking, nowadays since the Russians (who have the world's greatest supply) have flooded the market. I saw prices for some Ti alloys in the $10 US range a few months ago.

[Marshal]

The wheel used to be cast Magnesium, but I think they are now forged Aluminium, as this has a better still strength to weight ratio. Perhaps they could look at using Al-Li alloys if they really want to get exotic, but I'm not sure any of the wheel manufacturers has gone that far (yet).

[Sharky]

The price of the titanium that I posted is that oif pure 100% titanium. Buy alloys are much cheaper of course. But...I guess that if you need "homogeneous" metal then you can't have an alloy of any kind.

However....I might be misunderstanding that rule....in which case Ti alloys or Al'Li alloys could be used.

[desmo]

The cost of "pure" Ti is much closer to 100USD/kg. The common Ti alloys are all more expensive than CP(100%)Ti. The wheels appear to be made of Mg/Al alloys. The BBS wheels are said to use an alloy with a higher % of Mg than the OZs, hence lighter yet softer. Since the dimensions for wheels are given in the regs, the advantage of using Be alloy would be tempered. I think there may possibly be a small potential advantage to be had in unsprung weight if one could optimise and produce a design to take full advantage of Be alloy's excellent physical properties. Apparently the wheel manufacterers are not interested. CF wheels have been used in GP Bikes by Honda. They abandoned the idea after some nasty wheel failures however. This appears to be an area where teams are reluctant to experiment, preferring to use more or less off-the-shelf items.

[THR]

Far as i know they use mag alloy.
they are designed so that the forces are distrubuted around the wheel evenly, during side and braking and acceleration.

they are a very high tech peice of the car.
remember that about 10mm from them they have a glowing red disc. which is more than capable distorting a wheel if it wasnt made correctly.

a team uses 40sets of wheels each year (i think) and have a set life span for them. due to the amount of heat cycles they endure.
heat and light alloys dont go togehter too well so they have to really have a life.

if u ever pick an F1 wheel up u will be amazed at how light they are, its unbelievable, even with a tyre on!
they gotta be only 3kg or so. one finger lifts them!

the location that the wheel has on to the hub is also very important, so thats another reason y they are scat after a while.