Steel vs Aluminum Rims

[MNspiderman]

So I was just curious to why one would choose Aluminum/Magnesium over Steel or vice versa. All Nascar vehicles use lightweight steel rims. Is there a reason they don't use aluminum? Is it a flying shrapnel issue from being broadsided or something? I guess I just don't know Nascar rules very well. http://www.diamondracingwheels.com has some pretty cool steel rims, custom built rims, any width, backspace, offset, pattern imaginable. Very light too, and for about 1/3 the cost of some aluminum rims. Whats the pros/cons besides aluminum oxidizes and steel rusts. The only thing i can think of on why you would want aluminum is its nostalgic and it looks really good on a fiat spider. But so would deep dish racing steel wheels. I'm shopping for rims here in the near future so I value your opinions. Thanks

This is a very nice looking steel rim from diamond racing

[maytag]

I am uneducated on the topic, but that's never stopped me from offering an opinion!

I would imagine that it likely comes from a desire to reduce unsprung weight and rotational mass.
Aluminum (by design) is stronger than steel of equal mass / weight. o while the design of the wheel has a lot to do with the ultimate strength of the casting / forging, it would be true to say that aluminum wheels are lighter than equally strong steel wheels.

now, off the top of my head, I'd also guess that because of the characteristics of the designs of most wheels, the steel 'outer-rim' is likely much more substantial than that of an aluminum. This is important beyond the simple reduction in unsprung weight. When we talk about rotational mass, the further that mass is from the center / rotating hub, the more energy it requires to change its speed and trajectory. In addition, the greater the mass, the greater the gyroscopic effect... probably all but un-noticeable on a car, but a BRUTAL fact of OEM wheels / Brakes on motorcycles.

Just my guesses here.

[MNspiderman]

Is a 13 LB 13x7 aluminum rim better than a 13 LB 13x7 steel rim? I'm just digging for information, not trying to create a debate here. I'm sure there must be a reason besides someone saying aluminum is cooler looking or my car came with aluminum or its because you can make shapes in aluminum and not steel.

[So Cal Mark]

generally alloy wheels were lighter, but less forgiving when whacking curbs

[maytag]

Is a 13 LB 13x7 aluminum rim better than a 13 LB 13x7 steel rim?

Maybe. Maybe not.

First, let's start with your supposition on wheel weights:
Here's a link to some wheel weights:
http://www.wheelweights.net/
While not a comprehensive list, it is very useful. I sampled 15x7 wheels, as that's what I'm running.
There are 195 15x7" wheels cataloged there, beginning with the lightest (at 9.1 lbs), and working towards the heaviest (at 24.5lbs).
of note: the first / lightest of the steel wheels comes-in at #140, (18.5lbs) and it is not DOT approved. (Noptably; the Konig Holes that I have now weigh-in at 13.8lbs)
This mirrors my own experience as well: most steel wheels will not compare in either weight or strength to a comparable alloy wheel.

Secondly) let's capitulate, and say that you've found two wheels that you really like aesthetically, and that weight the same; One is steel, the other is aluminum. Is one better than the other? Here's the important question to answer that: WHERE IS THE WEIGHT?
As I stated in my previous response; the structural characteristics of the two materials differ in a way that will require different wheel designs. Steel tends to be quite strong in a flat plane, where softer Aluminum is stronger in a 'trussed' or extruded shape. So the Steel wheel will have more weight on the 'outer-rim', where the tire mounts, and an aluminum wheel will have more weight on the inner-hub, where the wheel mounts to the car. This means that a car with the aluminum wheel can accelerate and change direction faster than a car with the steel wheel.

You can also weigh-in (no pun intended) on the heavier wheel needing to have a heavier shock, as the damping will need to be greater to overcome the weight of the wheel.

So all-in all, here's what's better:
A Lighter wheel is (for most purposes) a better wheel. And a wheel with more weight in the center is better than a wheel with more weight on the outer rim.

Does that help?

[MNspiderman]

It does help. what you said reminds me of the gyroscope effect. (remember those toys?) example being a motorcycle wheel spinning on an axle. But your holding the axle. I've done this. Its quite an interesting feeling if you haven't done it before. Anyway. One with the weight centered straight through the center axis and another with the weight on the outer axis's (axi'?) being the two lips. Then turn the wheel and feel the difference. I see what you mean without me trying to explain this and not knowing all the terminology. Thanks

[Redline]

Auminum also dissipated braking heat better.

[maytag]

It does help. what you said reminds me of the gyroscope effect. (remember those toys?) example being a motorcycle wheel spinning on an axle. But your holding the axle. I've done this.

This leads me to think you've taken a Motorcycle school? Code? Pridmore? Other? (they all stole the idea from Freddie anyway )

[MNspiderman]

Who's Freddie Gyroscope?

[maytag]

no... Freddie.... as in: "Fast Freddie".... as in "Three-time-world-champ-Freddie-Spencer".

[MNspiderman]

Now there is a guy that knows his stuff. What else can ya say...

[maytag]

Now there is a guy that knows his stuff. What else can ya say...

o, there's LOTS more to say.

I am happy to call him a friend. But having said that; his biggest asset at the Freddie School was his lead instructor, Nick Ienatsch, who is now instructing the "Yamaha School of Champions, over at MMP, west of SLC.
http://www.millermotorsportspark.com/le ... le-school/

and Freddie's second-best asset there, Jeff Haney, now runs the KTM / Skip Barber Superbike school at Laguna Seca.
http://www.skipbarber.com/locations/mazda_raceway.aspx

I'm thinking I'll go do this one next fall.

[Tobi]

Since I have been looking for a 13x7 wheel for a while now to put 215/50 13th on it that looks like an interesting wheel.
Does anybody know the weight of a 13x5.5 Ironcross and do you guys think that even a spirited driver would notice the difference between steel and aluminum when the weight is the same?

[mdrburchette]

Diamond Racing wheels are what we use on our racecars. I know there are different weights available so you may want to ask them about this. We use steel wheels for racing because they bend vs breaking apart like magnesium can.

[stefhahn]

Well... I heard that argument various times but: is this true? Has anybody ever seen a broken forged mag wheel? Formula 1 cars still use mag wheels and (unluckily) even having seen several hard accidents even I cannot remember a single broken wheel.
ciao,
Stefan