Alloy wheels

After reading another tread within this forum i saw this posted...

I'll have a crack at bringing things back on topic . This is my opinion on the main reasons cars are now so heavy (not in any order):

1. Large alloy wheels are very popular and very heavy. Ironically, alloy wheels were initially made to be lighter but then when people started styling them, they became heavier than the steel wheels they replaced.

which got me thinking about the weight of wheels. Does any one know the weight of a F1 wheel and/or a le mans LMP1 wheel? Also does any one know the weight of a wheel of a road car derived race car eg WRC car or BTCC/WTCC car? Also have the weight of these wheels changed much over the years? And also any ideas what kind of materials they are made from?

Many Thanks

Just to update you all, I have found out that F1 wheels are made from a Magnesium alloy. there are 2 permitted types AZ70 and AZ80. the AZ detnotes what has been mixed in with the magnesium, in this case aluminium (A) and Zinc (Z). The numbers refer to the percentage mixed in, so in this case 7 or 8% aluminum and 0% zinc.

In WRC and WTCC the only regulations with regards to materials, are that they are made from a cast material.

Apart from this I have found the maximum permited sizes and minimum thickness etc for F1 and simular info for WRC however no indication on weight.

Any further help would be appreciated

Many thanks

Used F1 and WRC wheels are sold as memorabilia (see eBay etc.). Maybe you can find the weight there or ask the seller.

Used F1 and WRC wheels are sold as memorabilia (see eBay etc.). Maybe you can find the weight there or ask the seller.

A couple of years ago I bought the front wheels from Mark Webber's 2010 South Korea crash. It weighs in at 4.89kg, although it's for wet usage, which may or may not make a difference?

Edit: I just weighed one of the (dry) fronts from his massive crash in Valencia that year that I also bought, and it weighs the same, i.e. 4.89kg.

http://farm8.staticf...f6c499614_b.jpg

http://farm3.staticf...b2c243968_b.jpg

Edited by RogerGraham, 10 August 2013 - 14:34.

As I said on the other thread alloy wheels are lighter. Nearly always. Modern cars with low profile tyres have to have very strong rims as there is no tyre height to cushion the bumps. And even then most cars have out of round wheels. I know I fit tyres and balance them regularly as part of my business.
An equivilant strength steel wheel will weigh a good bit more.
I recently replaced the steel wheels with 3 ply wall tyres on my Landcruiser with alloy wheels and original size and load rating tyres. The difference is 25lb a corner. That is a 100lb, a small woman! The difference to drive is incredible, throttle response and braking is so much improved as is the ride quality. This is a extreme example maybe but even a factory 7x16 factory alloy wheel compared with a 6.5" steel wheel on a Ford Falcon is over 4lb each. And the alloys are officially stronger as they carry 25lb each more. And ofcourse disapate brake heat better. And look better. The weight actually is more when you include the wheelcover.

In smaller sizes steel wheels are lighter. They are also much better wheels. If you really wanted a light robust wheel from aluminium and steel you'd use a steel rim on an alloy hub. That has been done but it is too complex.

Another effect to consider is the wheels do not actually need to be any bigger than 15" even on a sports car. The extra size is purely for styling and adds a lot of mass and inertia. I remember going to pick up a 20" wheel/tyre 458 and being surprised at how stupidly heavy it was.

If Nascar can fit their brakes inside a 15" wheel, then so can Ferrari and so can everyone else.

Another effect to consider is the wheels do not actually need to be any bigger than 15" even on a sports car. The extra size is purely for styling and adds a lot of mass and inertia. I remember going to pick up a 20" wheel/tyre 458 and being surprised at how stupidly heavy it was.

If Nascar can fit their brakes inside a 15" wheel, then so can Ferrari and so can everyone else.

Nascar does not stop, they just slow down. Many better road cars would outstop them! For pure handling on a Sports Car on smooth roads a lower tyre outperforms the taller one. Though smooth roads are becoming a thing of the past.

For everyday family/ business motoring a 60 aspect rounder shoulder tyre is the best compromise. They drive and ride better in most circumstances and do not tramtrack [much] on worn out roads.

Greg, it must be very small cars that the wheels are lighter. Even a 13x5.5 is marginally lighter than its steel brother.
And on Ford Fiestas [and others] the steel rims just fold up on every third pothole. Alloys are much better though most of those too are every shape but round. A central offset rim does carry weight better as it spreads the load over more rim. Modern inset [or old outset] rims bend a lot easier. Though generally the cars drive nicer.

NASCARs certainly stop on road courses!

I have Compomotive alloys on my " toy car", 10*18" front , 11*18" rears.

They are not the lighest aloys by any means as they have a three part construction with steel outer rims.

However at least the steel rims can take some kerbing , and if bad , you just undo a zillion bolts and replace the outer rim only.

ONe thing that always amuses me about people who go up to bigger wheels is how silly the OEM discs look inside a much bigger rim.

That goes doubly so for 8" drums on the rear of some silly hatch with 18" wheels...

Crazy stuff!

Another effect to consider is the wheels do not actually need to be any bigger than 15" even on a sports car. The extra size is purely for styling and adds a lot of mass and inertia. I remember going to pick up a 20" wheel/tyre 458 and being surprised at how stupidly heavy it was.

If Nascar can fit their brakes inside a 15" wheel, then so can Ferrari and so can everyone else.

Pimp my wheels! When I had a Subaru Impreza GL (who needs a turbo for normal road use), my daughter refused to go in it as she said "What do you think it looks like with tin wheels!" - I replied that "From where I sat I couldn't see them"

There's a plumber's van in Potters Bar all decalled up and fitted with highly polished 20" alloy wheels; when all's said and done. it's still a van; the owner's life would have been immeasurably improved by his getting a life....

Let me fix that for you:

...the author of this post's life would have been immeasurably improved by his getting a life....

Much of what other people do is a stupid waste of time and money. I only do things others approve of.

Another effect to consider is the wheels do not actually need to be any bigger than 15" even on a sports car. The extra size is purely for styling and adds a lot of mass and inertia. I remember going to pick up a 20" wheel/tyre 458 and being surprised at how stupidly heavy it was.

If Nascar can fit their brakes inside a 15" wheel, then so can Ferrari and so can everyone else.

Have you ever seen the disc brakes used on NASCAR stockers nowadays?
They are a looooooooong ways away from the first one's Penske used.

Some one, probably on this forum, once said that if one cannot fit the brakes within a 17'' wheel, any extra size is useless-pointless.

Now that said, with the drisk brake once developed by a independent stock-car parts maker, and never adopted; the v-shaped brakes used on Harley road-race bikes forty years or so ago, and even the possiblility of carbon-fibre drum brakes, (heat makes carbon brakes work, drums heat quicker ) brakes have not really advanced for a long time.
-----

Steel wheels-- As I found out when I bought the only new steel wheel in my life, there is a reason they are as thick as they are.

While the OEM wheels on my '66 Plymouth Fury that were twenty plus years old were fine, the one I replaced after person who ran a stop-sign wrecked it, it rusted through in less than ten years.

Edited by Bob Riebe, 12 August 2013 - 21:42.

Have you ever seen the disc brakes used on NASCAR stockers nowadays?
They are a looooooooong ways away from the first one's Penske used.

Some one, probably on this forum, once said that if one cannot fit the brakes within a 17'' wheel, any extra size is useless-pointless.

Now that said, with the drisk brake once developed by a independent stock-car parts maker, and never adopted; the v-shaped brakes used on Harley road-race bikes forty years or so ago, and even the possiblility of carbon-fibre drum brakes, (heat makes carbon brakes work, drums heat quicker ) brakes have not really advanced for a long time.
-----

Steel wheels-- As I found out when I bought the only new steel wheel in my life, there is a reason they are as thick as they are.

While the OEM wheels on my '66 Plymouth Fury that were twenty plus years old were fine, the one I replaced after person who ran a stop-sign wrecked it, it rusted through in less than ten years.

On your last point was that the fault of the wheels or the poor "paint job" (or whatever process was used) to protect the steel?

Rims normally rust from the inside. All the moisture trapped in there with the use of tubes.
Though I have seen some very rusty rims recently that people wish to drive on. Scrap metal really.

On your last point was that the fault of the wheels or the poor "paint job" (or whatever process was used) to protect the steel?

Good question but it was too many years ago.

I replaced it with a junk-yard oem (which happened by the grace of God) and the gent who put the tire on the rim said that new steel wheels at that time (which finding of, for a not incredibly high price, was already becoming hard to find) were made of cheap thin steel.
He said what I had happen was not all that uncommon.

which got me thinking about the weight of wheels. Does any one know the weight of a F1 wheel and/or a le mans LMP1 wheel? Also does any one know the weight of a wheel of a road car derived race car eg WRC car or BTCC/WTCC car? Also have the weight of these wheels changed much over the years? And also any ideas what kind of materials they are made from?

F1 wheels are made from magnesium forgings that are 100% machined. The wheels are likely less than 8 lbs each. F1 tires are also incredibly lightweight.

which got me thinking about the weight of wheels. Does any one know the weight of a F1 wheel and/or a le mans LMP1 wheel? Also does any one know the weight of a wheel of a road car derived race car eg WRC car or BTCC/WTCC car? Also have the weight of these wheels changed much over the years? And also any ideas what kind of materials they are made from?

F1 wheels are made from magnesium forgings that are 100% machined. The wheels are likely less than 8 lbs each. F1 tires are also incredibly lightweight.

F1 wheels are made from magnesium forgings that are 100% machined. The wheels are likely less than 8 lbs each. F1 tires are also incredibly lightweight.

Earlier in this thread I posted a photo of a 2010 Red Bull front wheel, weighing in at ~4.89kg, or ~10 pounds 12 ounces.

I don't think it would make the slightest difference to ride/handling if those wheels were made of depleted Uranium. Actually might get the CoG slightly sorted and provide some of that legendary 'road hugging weight' we all secretly lust after.

What came first - the huge wheels, or the huge tyres?

Bring back the motor buggy...

You spoke too soon... I'll get my Drizabone.

The effin monster doesn't even fit in the painted parking space to begin with.

Kinda OT but here's another way to add some road hugging weight--

http://jalopnik.com/...ating-921147122

The effin monster doesn't even fit in the painted parking space to begin with.

In a story recently I wrote, "The Edsel might not be the biggest blunder in Motor City history..."

Someone asked, incredulous: "What!? what was a bigger mistake than the Edsel?"


That's an easy one, I said. We could start with the Hummer Division.

To me that is what any wheel of more than 17 inch diameter looks like; it is just that the largest look like a childish toy.

Please tell me they're not steel tyres.

F1 wheels are made from magnesium forgings that are 100% machined. The wheels are likely less than 8 lbs each. F1 tires are also incredibly lightweight.

I doubt that very much as pure magnesium is flammable, remember 1955 Le Mans, as a matter of fact I'm sure there's something in the rules about it.

But some sort of high-pressure die-cast Al-Mg-Zn alloy I can imagine.

12.3 Wheel material:
Wheels must be made from AZ70 or AZ80 magnesium alloys.

From http://www.formula1....s/8712/fia.html

And here is the spec for the AZ80 alloy, it seems to be a wrought quality however, why I stand corrected on that part.

http://www.matweb.co...p...1b0e&ckck=1

Not forged to shape though, more like extruded bar-stock and machined from there it seems.

Edited by Rasputin, 18 August 2013 - 07:46.

I picked up an F3 rear with tyre today. it was quite light and also badly cracked. Being sold as a coffee table!

All those that are worried about magnesium being flammable should try an experiment. Get a magnesium wheel and set it alight.
I bet I can set fire to steel using a match before you can set fire to a magnesium wheel with a blowtorch.

I thought F1 wheels are currently mag alloy forgings but I am ready to be schooled on the matter.

I believe an alloy like AZ80 is far less flammable than the pure Magnesium used in the Honda RA302 of Jo Schlesser or the 1955 Le Mans Mercedes, both which burned in a spectacular fashion.

As for manufacturing, this piece seems credible to me; http://www.formula1-...net/wheels.html

Extrusion plus die-forging, guess you learn something everyday, at least I did?

Heated and stamped out? Was my guess..

To summarize some of the above and to put into perspective some of the points made previously-

These days most OEM and Aftermarket alloy or “Mag” wheels are made from an alloy of Aluminium and are usually manufactured by the Low Pressure casting process. Originally these wheels were intended to be lighter than the equivalent size steel wheels that they were replacing, - and with judicious design they can be. Unfortunately “fashion” seemed to get in the way, and as previously noted the alloy wheel sometimes finishes up being heavier than the steel wheel it replaced.

However, when it comes to real weight saving, as desired in a “pukka” racing car, Magnesium is the better proposition as it is approximately 30% lighter than aluminium.

Nevertheless pure Magnesium is not the answer.

In all cases an alloy of Magnesium is used, and as stated previously, Aluminium and Zinc are usually the primary alloying elements. This is to enhance the mechanical properties, machinability, corrosion resistance, etc. of Magnesium. In most cases the Magnesium alloy consists of around 90% pure Magnesium.

Back 30 – 40 years ago most Magnesium alloy wheels were typically manufactured by casting. This is not an easy process to control as it needs to be carried out in an inert atmosphere and often produces shrinkage voids, hot tears, porosity etc.. But now, with the availability of very large forging presses and CNC machining the old days of producing Magnesium wheels by casting has virtually disappeared.

Although the forging process is much more expensive than casting, the advantage gained is that it produces a wrought structure which greatly enhances the mechanical properties of the Magnesium alloy which in turn enables thinner wall sections and therefore further lightening of the wheels.

Unlike the casting process, forging also eliminates micro-porosity and therefore overcomes the possibility of leaking rims.

As for Magnesium or Magnesium alloy “catching fire” it depends on the circumstances. Thin magnesium alloy shavings can be ignited with a match or even a blunt machining tool and magnesium powder / dust can ignite explosively with a spark. Solid Magnesium and most Magnesium alloys will only ignite and burn in a normal atmosphere if their temperature reaches around 600 degrees C - i.e. as a result of a petrol fire, or if you’re unlucky the friction of a rim dragging across the bitumen at high speed.

To put out a Magnesium fire it needs to be completely smothered and starved of Oxygen – not easy to do without the right equipment. Water is useless as it only provides more oxygen which in turn feeds the fire.

Thanks Kaydee! 

For those that don't know, Kaydee made some of the best and nicest looking alloy wheels around. 

Thanks Kaydee, great briefing. 

These are my favourites. I just need to build the car to stick them on.

These are my favourites. I just need to build the car to stick them on.

 

That car of yours is maturing like a fine wine Mike...hey, it was kind of wine coloured

To summarize some of the above and to put into perspective some of the points made previously-

These days most OEM and Aftermarket alloy or “Mag” wheels are made from an alloy of Aluminium and are usually manufactured by the Low Pressure casting process. Originally these wheels were intended to be lighter than the equivalent size steel wheels that they were replacing, - and with judicious design they can be. Unfortunately “fashion” seemed to get in the way, and as previously noted the alloy wheel sometimes finishes up being heavier than the steel wheel it replaced.

However, when it comes to real weight saving, as desired in a “pukka” racing car, Magnesium is the better proposition as it is approximately 30% lighter than aluminium.

Nevertheless pure Magnesium is not the answer.

In all cases an alloy of Magnesium is used, and as stated previously, Aluminium and Zinc are usually the primary alloying elements. This is to enhance the mechanical properties, machinability, corrosion resistance, etc. of Magnesium. In most cases the Magnesium alloy consists of around 90% pure Magnesium.

Back 30 – 40 years ago most Magnesium alloy wheels were typically manufactured by casting. This is not an easy process to control as it needs to be carried out in an inert atmosphere and often produces shrinkage voids, hot tears, porosity etc.. But now, with the availability of very large forging presses and CNC machining the old days of producing Magnesium wheels by casting has virtually disappeared.

Although the forging process is much more expensive than casting, the advantage gained is that it produces a wrought structure which greatly enhances the mechanical properties of the Magnesium alloy which in turn enables thinner wall sections and therefore further lightening of the wheels.

Unlike the casting process, forging also eliminates micro-porosity and therefore overcomes the possibility of leaking rims.

As for Magnesium or Magnesium alloy “catching fire” it depends on the circumstances. Thin magnesium alloy shavings can be ignited with a match or even a blunt machining tool and magnesium powder / dust can ignite explosively with a spark. Solid Magnesium and most Magnesium alloys will only ignite and burn in a normal atmosphere if their temperature reaches around 600 degrees C - i.e. as a result of a petrol fire, or if you’re unlucky the friction of a rim dragging across the bitumen at high speed.

To put out a Magnesium fire it needs to be completely smothered and starved of Oxygen – not easy to do without the right equipment. Water is useless as it only provides more oxygen which in turn feeds the fire.

 

Any metal that reacts with oxygen is theoretically capable of "burning".  This would include aluminum, magnesium, or even titanium.  The key factor for getting a metal to "burn" is providing sufficient heat to liquify and vaporize the metal so that it can properly mix with the available oxygen gas.  A metal in a solid or liquid state is not capable of producing an energetic oxidation reaction (ie. combustion).  Aluminum or magnesium will only initiate and sustain combustion when there is sufficient heat input to liquify and vaporize the metal.

 

A good example of how aluminum is "burned" to produce huge amounts of thermal energy is that of solid fuel rocket engines.  These rocket engines add aluminum particles to the solid fuel mixture, and when these aluminum particles burn they produce huge amounts of thermal energy.  Far more than any other type of rocket fuel.

You have obviously never heard of pyrophoric iron. This will spontaneously ignite in air with no heat supplied because it is extremely finely divided so that there is an enormous surface area relative to the mass for the oxygen to react with. It is not necessary for the metal to be vaporised in order to burn.

http://youtu.be/5MDH92VxPEQ?t=27s

How to make solid steel burn.

 

1) Steel wool

2) 9V battery

 

Jam the terminals of the battery into the steel wool.

 

A great wet weather fire starter, tho I prefer my block of magnesium, a penknife, and a flint.

A bloke I worked with got sick of one of his neighbours pinching coal off his coal heap, so he stuck a couple of lumps of magnesium in the front of the pile and waited.
A couple of days later the arrival of the fire brigade up the street pointed the way to the offending neighbour. 

In the early seventies Frank Matich's boys were machining some new wheels...

 

During the process either a wheel or the swarf caught fire. They had to race on the old wheels that weekend.