Alloys - why have them? - Bob H
OK so alloys reduce unsprung weight and look good after cleaning. I wonder however just how much they improve road holding. Or are there other advantages?

On the debit side they add in typically £300 -£400 to the cost of a family car. They are a pain to clean and neglecting this chore leads to pitting; they also show the results of any kerbing.

The problem is that they have become mandatory on the higher spec models of most cars. SWMBO has a Yaris Verso GLS which is used in shopping trolley mode. The problem was to get ABS(essential) and A/C(desirable) you had to order the GLS - which came with Alloys. (ABS is now standard on GS).

I question why manufacturers feel that we need, or want, alloys on anything other than a sports car.

Bob H
Re: Alloys - why have them? - Andrew T
You have forgotten to mention the set of locking nuts that are necessary to hang on to the scarcer varieties. Having said that, my impression is that alloys are no longer at the top of the list of trendy things to nick.
Re: Alloys - why have them? - andy bairsto
Alloys are heavier than steel wheels
Re: Alloys - why have them? - Darcy Kitchin
Visible evidence that you have the means to pay for a top spec car, therefore status, like front foglights, spoiler etc.

And the're easier to heft around if you have a puncture.

Worth it? You decide.
Re: Alloys - why have them? - Pete
Well they look quite good but on a 4x4 off roader? If used seriously used off road they must get really damaged.
Re: Alloys - why have them? - Ian (cape town)
Saw the ultimate add-on car today - Red Astra with clear light clusters, window tinting, Alloys, sills all over, eyelids, debadged, non-standard door mirrors, stainless exhaust extension, thumping stereo- the whole bang-shoot!
Fog lights on (It had been light for 3 1/2 hours, and there ain't a cloud in the sky)
I bet the add-ons were worth about 20% of the value of the car!
Driver wearing the obligatory baseball cap.
Everybody in the traffic took one look and said "what a prat"..
Re: Alloys - why have them? - Lee H
Ah, yes but that's what he was after....

"Everybody took one look...."
Re: Alloys - why have them? - John Slaughter

Absolutely - the last thing you need on a small car used around town are alloys that are irreparably damaged the first time you touch a kerb.

My last few cars have had alloys - no option - as Darcy says they are now part of the 'image' provided by the manufacturers which shows you haven't bought the base model (in fact it's worse - there are various alloy designs to show exactly which model you've bought in the range)

Problem is I'm paranoid about kerbing them - my car can be recognised because it's always 6" further out than the others! Missus hates using it in case she damages the wheels.

Looking down the average high street I see several examples of really wrecked aloys - and I wonder what is the hidden cost to car buyers for the the second hand trade to refurbish/replace the bad examples they can't put on the forecourt.


Re: Alloys - why have them? - Darcy Kitchin
What about the kerbing bands fitted to some tyres in the '80s designed to stop you bumping the alloys. Next to useless, unless your hearing was very keen i.e you heard the tyre kiss the kerb first.
Re: Alloys - why have them? - Dan J
The handling on my Cavalier is typically Vauxhall and dreadful with a large tendency to understeer. I wanted to fit wider wheels to the car to improve cornering however for all the reasons mentioned above I did NOT want alloys. I have no desire to turn my car into a "Kevinmobile" (no offence intended to anyone called Kevin, just how they get referred to in my circles!) and have been looking for a wider set of steel wheels.

I thought these would be easily available (people upgrading cars in the US often fit steel as opposed to alloy wheels) but in the UK you cannot get hold of them unless they are for 4x4.

If someone could point me in the right direction if they know anywhere that'd be great, but I do agree that alloy wheels are a damn nuisance (also a pain to have balanced!)
Re: Alloys - why have them? - ChrisR
Is it necessarily true that alloys are lighter? Isn't it just that they tend to be fitted with low profile tyres? Someone will correct me, I'm sure, but don't F1 cars use steel wheels?

Re: Alloys - why have them? - Andy P
F1 cars use magnseium alloy wheels, which are avaliable for a select few road cars (McLaren F1 for example). They are extremely light and extremely expensive.

Re: Alloys - why have them? - IO
Obviously (light-weight) alloys *should* be lighter than steel wheels, and the original idea was that as anything that moves *on* a car has to be moved round as well as along, and so uses up twice the power, making the wheels, if nothing else, out of a light-weight alloy is a "good thing".

Unfortunately from the comments above it would seem that no engineering goes into their design, just styling.

Reminds me of a story I once heard about the Denovo (I think) run flat tyre. Allegedly the marketing chaps didn't like the tread pattern and sketched out a more appropriate "design". Which apparently contributed to the fact that they performed better after they were punctured than before :-(
Re: Alloys - why have them? - Carlos the Jackal
Alloys heavier than steel wheels hmmm?

I couldn't imagine the weight of a steel wheel in the size my motor uses (as standard) 17inch x 7inch wide. The torque steer would also be unbelievable...

Steelies are for off-roaders and shopping cars (the point of the original post I think).
Re: Alloys - why have them? - David W
I would have guessed alloys were lighter but don't actually know.

Anyone a full sized steel spare on a car with alloys?

Sneak the bathroom scales out under cover of dark and tell us.

Re: Alloys - why have them? - Stuart B
"Steelies are for off-roaders and shopping cars"

and for the set of spiked winter tyres
Re: Alloys - why have them? - Rob
Yep. Alloys are usually heavier.

Also, on up-market cars (S-class/Bentley) it's only very recently that you see them exclusively with alloys.

Alloys are impractical, marketing guff. Well thought out wheel trims can look much better - e.g. Saab stainless steel trims, Old XJ40 trims with prise off wheelbolt covers, Citroen SM. Peugeot even do a trim that exactly copies the pattern of their alloys, and you're hard pressed to tell them apart.

Getting technical - Vin
The force transmitted through to your car upon hitting a bump is directly proportional to the ratio of unsprung weight to sprung weight. As an example, a 2.5 ton Bentley hardly wavers when the wheels hit a bump; the ratio is so high that very little force is transmitted through to the body ogf the car. This means the suspension can be tuned to keep the wheels on the road rather than trying to damp out movement.

When a racing team spends a fortune reducing the weight of every component to its absolute minimum, then if it fails to address unsprung weight it ends up with a car that leaps over every piece of grit on the track. It then becomes difficult to keep the car's wheels on the road (for steering, etc). So, the wheels are made out of unobtanium alloys in order to gain weight reduction with the attendant benefits of better handling. (Wheels are part of this, but ever felt a racing slick? Weightwise, it feels like it's made of paper)

Finally, gyroscopic forces are reduced, making it easier to change direction, though this effect is pretty minimal.

So, alloys do two main jobs. They make your ride more comfortable and they keep your tyres in contact with the floor.

That is, however, with two caveats: 1. The alloys must be lighter than equivalent steel wheels and 2. The suspension must have been designed (or altered) to suit the wheels.

However, I tend to agree - they have become a necessary fashion item.


PS All of the above courtesy of John Robinson's technical motorcycling ramblings. Reproduced via my flaky memory.
Re: Getting technical - Piers
I had some alloys for a Mini - When swapping the alloys for steels the weight difference was noticable - the alloys were 'much' lighter. These were mini-lite copies so the design was pretty standard and I think a good original design based on getting air to the brakes and strength. The wheels on the Italian Job minis were swapped to alloys as the steel ones collapsed when landing after jumps.

I'm sure some of the alloys fitted to cars are excessively heavy and the design is responsible for this. The manufacturing process for producing alloys differs greatly depending on what they are for - cast, forged or even spun (rims). Of course if it's only a couple of KG on a 1500kg car it doesn't matter and won't matter to the average punter.

For a car like a Caterham you can have very light magnesium wheels with x-ply FF racing tyres. These are about 1/2 the weight of other wheel / tyre set-ups and well worth the money on the track (£215 wheel, £80 a tyre approx). The other benefit of alloy wheels is their stiffness - steel wheels flex under side loads (cornering) which can cause handling anomilies or breakages.

Also alloys often look nice and don't fall off when you go round corners like wheel trims.....

Re: Alloys - why have them? - Bob H
Surprised that some feel alloys could be heavier than steel wheels. I have done a little research on the internet and below is something I cut and pasted from a firm selling alloy wheels. (Mark - Brazil I use the RH button mouse click method!!)

"Perhaps a major reason why alloy wheels are chosen is to enhance appearance. However, alloy wheels do have other advantages.

According to Guy Coad, Sales Representative for ROH Wheels, who make and supply alloy wheels for major car manufacturers, alloy wheels are lightweight, which can improve a vehicle's handling characteristics.

"Because alloy wheels are lightweight, there is less stress on the vehicle's suspension and less stress to the driver, especially without powersteering. The vehicle becomes lighter to steer," Mr Coad said.

"The life of suspension components in the front end is also extended."

Alloy wheels are also popular because of their ability to dissipate heat, which improves brake performance and also extends the life of the brakes. "

The site is American which makes the notion of Alloy wheels without powersteering difficult to envisage.

Must try to find out the weight difference.

Bob H
Re: Alloys - why have them? - Dave N
That's correct, regular alloys are not always lighter. Only pukka mag aluminium.
Re: Alloys - why have them? - dan
Hurrah for Piers the man-o-reason,

Steel wheels lighter than alloys on the average car?
This must mean that alloy materials are weaker than steel... Even if you assumed that the alloy weighed as much as steel (which it doesn't) you are effectively saying that more/thicker supports are required on alloys to acheive the same performance as steel wheels.

So why do alloys have spidery three prong designs and steel designs are still inspired by biscuits? (Note that alloys have higher melting points and are much harder to work with...)


Value my car