Does anyone make a performance-oriented steel wheel?

[rpt50]

I am not talking about a a stamped steel wheel. I'm talking about something made with a high quality chromoly steel that would be comparable in weight to aluminum. Is there any such product?

 

[maestromaestro]

Performance means less unsprung weight. Steel means heavy. So, I doubt that outside of some weird off-road endurance market there is one. Why would you want one anyways?

Sent from my Pixel 3 XL using Tapatalk

 

[rpt50]

Does steel really mean heavy? Consider what has happened in motorcycle racing. Fifteen years ago aluminum frames were all the rage, and guys left and right were swapping frames, buying new bikes, etc. Now the situation has changed considerably, and steel frame bikes are dominating podiums everywhere. Also consider sprockets used on racing motorcycles. I have switched to a chromoly alloy sprockets that come extremely close to aluminum in mass (a trivial difference in unsprung weight), yet last at least 3 times longer. If I could buy a durable steel wheel comparable to an aluminum wheel in mass, I would do it in a heart beat.

I'm finding steel racing wheels online that are quite comparable to aluminum in weight, but not in sizes that would work on our cars.

 

[Bizzareo]

The thing I'm trying to find is a wheel that is a little smaller, but retains airbag.

 

[jeffreylyon]

I'm finding steel racing wheels online that are quite comparable to aluminum in weight, but not in sizes that would work on our cars.

Example?

 

[maestromaestro]

Well, two points. Steel, by nature (what with the density) is heavier than aluminum or magnesium. So, for the same size wheel, you'll heave a lot more weight. Secondly, you are mixing the notion of weight/mass and unsprung weight.

The frame of a motorcycle is not the same than a hunk of metal hanging from the hubs on the car corners. In a bike, the frame is part of the suspension, if you will - in a car, the wheels are not, so it's unsprung/unsupported.

I also have to question the notion of "durability" of the wheel - I have had hundreds of thousands of miles on alloy wheels and yet to encounter any problems of their not lasting.

Having said that, poorly fabricated cast alloy wheels have been found to spontaneously disintegrate under the stresses of track driving; hence the advice to get forged wheels if you don't mind paying the premium. Or, as in the case of GT350R - carbon fiber ones, at $4k a pop...

Sent from my Pixel 3 XL using Tapatalk

 

[M-Sport fan]

One other factor to consider; in order to get to the same weight as a quality alloy wheel, any 'racing' steel wheel will by necessity be of a MUCH thinner gauge steel (even the BEST steel alloys), so therefore also of a reduced strength.

 

[dmb]

Or, as in the case of GT350R - carbon fiber ones, at $4k a pop

do ya think the dealer's might have some take offs that they took off for some 28 inch spinners?

 

[maestromaestro]

do ya think the dealer's might have some take offs that they took of for some 28 inch spinners?

That’s a whole different demographics, from what I see...

 

[rpt50]

Let me throw in my disclaimer that I'm a motorcycle guy and long time motorcycle racer, but not a car guy at all, and have only recently discovered how fun cars can be (starting with a miata about 5 years ago). So my car experience is very limited and maybe I totally misguided on this.

As I have started looking into new wheels for my FIST, I was surprised at how often aluminum wheels seem to get damaged. That's what got me thinking about steel.

Regarding steel vs aluminum for structural purposes, obviously they have different qualities, but for years in the motorcycle community the consensus was that aluminum would give you a stronger and lighter frame. Well, that turned out not to be the case, and European manufacturers that stuck with steel now make considerable lighter bikes than their Japanese rivals, in part due to lighter steel frames.

I am well aware of the effects of unsrpung weight from my experience with motorcycles. That's why I gave the example of steel alloy sprockets that have far greater durability than aluminum sprockets, but are very nearly as light. They also cost more, but the greater durability makes it will worth the cost.

As an example of steel wheels that seem like they would be plenty strong, with comparable mass to aluminum wheels, check out the Aero Racing page. Am I missing something entirely? I would think wheels built for those conditions would be plenty strong for street use. Does anyone make wheels like those that would fit our cars?

 

[maestromaestro]

Let me throw in my disclaimer that I'm a motorcycle guy and long time motorcycle racer, but not a car guy at all, and have only recently discovered how fun cars can be (starting with a miata about 5 years ago). So my car experience is very limited and maybe I totally misguided on this.

As I have started looking into new wheels for my FIST, I was surprised at how often aluminum wheels seem to get damaged. That's what got me thinking about steel.

Regarding steel vs aluminum for structural purposes, obviously they have different qualities, but for years in the motorcycle community the consensus was that aluminum would give you a stronger and lighter frame. Well, that turned out not to be the case, and European manufacturers that stuck with steel now make considerable lighter bikes than their Japanese rivals, in part due to lighter steel frames.

I am well aware of the effects of unsrpung weight from my experience with motorcycles. That's why I gave the example of steel alloy sprockets that have far greater durability than aluminum sprockets, but are very nearly as light. They also cost more, but the greater durability makes it will worth the cost.

As an example of steel wheels that seem like they would be plenty strong, with comparable mass to aluminum wheels, check out the Aero Racing page. Am I missing something entirely? I would think wheels built for those conditions would be plenty strong for street use. Does anyone make wheels like those that would fit our cars?

I can only repeat myself - your quest of "strength" because the wheels seem to get damaged easily is a peculiar pursuit. Damage is a result of plastic deformation of a material, which is to say that the stress imposed by say, an impact against a curb, exceeded the material's yield strength. To that end, aluminum alloy commonly used for "alloy wheels" is 356, with the T6 heat treatment. That gives it 20 ksi of yield strength and 30 ksi of ultimate tensile strength. Modern steels, like 955X used for automotive wheels, have 55 ksi and 70 ksi of YS and UTS, respectively. The higher the strength, the more material is resistant to deformation (and has higher hardness, too). So, technically, you can make a thinner steel wheel that would, for the same x-section, have the same strength (that is, will deform at the same imposed stress).

But, steel is 2.5 times heavier than aluminum, presents manufacturing challenges, subject to corrosion under atmospheric conditions (hence the paint or powder coat), and has aesthetics-related issues. As I noted before, my anecdotal experience indicates that Al wheels are not overly prone to damage - this is to say, that if I damaged my Al wheel by hitting a pothole, I would have likely damaged the steel wheel as well.

Your examples of steel frames and steel sprockets are not directly applicable - the frame of a bike (just like that of a bicycle) can be made from high-strength steel (higher than the 955X), as the form factor is not that of a wheel, so HS tubular goods can be easily fabricated (it does impose considerable onus on the quality of the welds though). The types of steels used for that are plentiful and can be heat treated to dial in the desired mechanical characteristics, such that the YS and the UTS are far greater than the strongest aluminum alloys used in the aerospace industry. [On a side note, whereas I am aware of the "reversion" for the HS steels for the bicycle frames in the 90s - from aluminum alloy, it would seem that carbon fiber is the material of choice, so it is rather odd that the motorbikes are using steel...]

So, given the above, and factoring in the cost of fabrication of a HS material (meaning - expensive), steel wheels are not a common choice. The ones that are out there are heavy, and affect the car's driving dynamics. Aero Racing offers wheels that are sized up to 15"; most alloys start there. And, for a 15x9 steel wheel you are carrying about 5-6 pound penalty, so for 4 wheels (not 2 - ), you are looking for 25 more. Now, for a street driving that may not be much (although you will be paying more for gas), but for a track - that's substantial. And, you bought a FiST - which means that you want a light car, with a good lb/hp ratio. Hence the question - why would you want to make it heavier?

 

[rpt50]

Thank you for the explanation, I certainly don't want to make it heavier. I want to make in more versatile. What started all this for me was the desire to move to a smaller wheel and larger tire to get a little more protection, without ruining the handling dynamics of the car. We do the same kind of thing all the time with the rear wheel of off road motorcycles. I live in Atlanta which has ridiculous traffic and is constantly under construction. Huge potholes appear that weren't there when you went to work the previous day, and they have a nasty habit of covering service holes in the road with huge steel plates. I've already ruined one tire on a plate, and at 57 I will readily admit that I don't see as well as I used to in the dark, rain, and less than optimal conditions, I've hit potholes in the dark on unfamiliar roads that send such horrible jolts through the whole car that make me worry that I'm really going to damage something. This is enough of an issue that I often find myself choosing to drive my truck so I don't worry about damaging the car. I am also about to retire, and I bought this car with the thought of taking lots of road trips that I could never do in my miata (no room for wife, dog, bags, and guitar). The last thing I want to happen is to be stranded somewhere where I can't get a tire/wheel fixed. Did you ever see that Top Gear episode where Jeremy Clarkson was trying to get a tire for the Merc somewhere in the hills of North Carolina?

I was thinking that I could go with a 16" wheel to get a little more protection and cushion. Given the published weights for the 15" aero wheels (which are cheap!), it sure seems like they could make a 16 x 7 in the ball park weight range, and I would be more than willing to pay a premium for steel. But if it does not exist, the point is moot.

What price point do you think I could get a 16" aluminum wheel with at least comparable durability to the OEM wheel? Should it be something other than gravity cast? Can I assume that something sold on a well-known site like Tire Rack would be equivalent to OEM? Some of the local wheel shops I've visited seem a little shady, and they are far too concerned with cosmetics in my opinion.

 

[jeffreylyon]

There is a 16x8 option for the 4x108 PCD of the FiST. There are several 15x7 and 15x8 options as well. Whether these are as tough as the OEM is questionable; OEM wheels are usually pretty tough (and heavy). However, you'd use a higher profile tire on either the 15" or 16" wheels, gaining more cushion and protecting the wheels more. Flow-formed aluminum wheels will be multiple pounds lighter than the same-sized steel versions as well as the OEM wheels, decreasing unsprung weight and further improving.., well, everything. There are quality flow formed 16" and 15" options at less than $220 a wheel - some much less. Coupled with a higher profile tire you will have better ride, better performance and, perhaps, at least as much pot-hole resistance. Unless you're ready to hire a lab to test the OEM tire/wheel combo with a replacement, nobody can tell you, for sure, if one is tougher than the other.

I run a couple of sets of 6UL 17x8 wheels with 215/40 and 215/45 tires. Everything is better: ride, acceleration, braking, turn-in, etc. I haven't dinged a wheel (and Pittsburgh streets are as crappy as anywhere), but this is not really my DD.

While I use Tire Rack exclusively for tires I probably wouldn't buy wheels from them. Search the forums - this topic has been talked to death.

 

[maestromaestro]

With a more expansive explanation, I can see your reasoning. If you still would like to go with the steel, it's just a matter of fitment - there are online calculators that would show you what happens if you change the rim size and offset.

The challenge is the stupid 4x108 bolting pattern on the FiST. You're not likely to find many steel options.

If you do, then perhaps consider having another set of wheels (say, OEM Rados) for the track. But, you have a Miata, so you're all set.

The best alloy wheels "out there" are forged, but they will be expensive relative to the cast/flow formed ones.

Don't discount the local shops - they do frequently look like there's something else is going on in the back -)), but there you will have an advantage of checking the fitment directly. Having said that, if you stay within the offset range of OEM, you should be OK. If you go to alloys, step down to 16 with a bigger sidewall - that should give you a measure of protection.

But - the potholes you described are massive, so - maybe just drive the truck??



Sent from my Pixel 3 XL using Tapatalk