I'm curious if anyone here selects their rims for stiffness, and if so are steelies any less stiff than alloys?

My '65 Satellite runs steelies and I discovered accidentally they flex a little. I never thought about it before. Last summer I heard this weird squeaking sound every time I turned a hard right and after weeks of head scratching investigation, I traced it to one hubcap with one set of teeth that weren't grabbing tightly on the rim - and the teeth would squeak on the steel rim edge in corners.

So is "rim flex" an issue for any of you when auto crossing or track racing?

BACKGROUND:
I'm currently using 14x6.5inch Ford steel rims to allow slightly wider 14x7 tires on rims that still take the OEM 14" hubcaps (not poverty caps) for a factory stock look.

I am considering departing from the stock look and go with 15+ diameter rims to accommodate disc brakes for improved safety and performance and eventually take the car to a track day. Question is what to go with - 15in steelies are inexpensive, but are they really any good? Larger 16-17" would be even better, and then I'd might as well go with alloys. I think.

Thanks,
- Art

Only time I ever ran into a hubcap squeak issue was when the Dodge dealer so over tightened the lug nuts on my MIL's Colt that my Impact gun would not remove them. They even managed to stretch the thread on the lugs and the nuts, all of them, on each corner. I suspect they flexed the rims too.

So I simply bent the springy fingers out more and no more squeaks.

just curious. how much [if any] did you have to remove from the center register hole on the ford rim to fit over the axle hub ? what year and model did the ford rim come from ? i have found over the years that while the ford rim has the same 5 on 4 1/2" bolt pattern, the center hub register hole is smaller than the hub register on the mopar axle and front hub, thus requiring the center hole to need opened up to fit. the mopar wheel, however, has a larger center hole than the ford, requiring no mods to bolt up and use in ford applications. the center bumps are also larger on the ford wheel if you want to use dog dish caps of the later [smaller, 68 on i think] diameter. i think the ford bumps are close, if not the same location as the 62-66 or so larger dog dish caps, but i have never checked to see if those caps fit the ford wheels. as supercuda said, i have also just bent the retaining tangs outward to quiet the squeeky wheel cover or trim ring when needed. late cop wheels are heavier than the standard steel wheels of that era, made from thicker material to take extra abuse from pot holes and curbs, and yes, they flex less than the standard wheel as well.

I had to remove some material with a hand file for the rims to fit over the Mopar center register. IIRC the front rims fit easier with less material removed. On the rears I definitely removed more material for the center register to get them on.

I don't recall the year(s) my Ford rims came from.



I haven't tried them either. I'm not using dog dish. My goal with the Ford rims was to enable me using the full 14in "spinner" style hubcaps that were stock for '65 Satellites, with 7" wide tires. For dog dish I would have just bought new Chrysler OEM style 15x7's steelies from Summit.



Yes, this worked for me too, and the squeak went away.



So I think the answer to my question whether flex actually matters on a steel vs alloy rim is..

"Meh"...


- Art

67 -- The factory steel RALLEY rims do flex.. and can break at the center section where they make their radius bend coming out... where the center cap would meet with it. I believe that was a factory design fault... not truly tested under hard/sever cornering loads, such as suing soft-compound tires, or similar "drifting" sideways. It happened to one of rear rims a long time ago. Since then, I would never again use those specific MOPAR RALLEY rims for autrocross, etc. street/hwy driving is OK as long as you don't push hard in the corners... repeatedly... they will flex and eventually break.

On the other hand, cop-car style rims (15x7, 15x8 Super Coupe) are probably a better steel rim to endure cornering.

Scott Harvey and co. recommended using double wheel spiders (centers) in the Rally Tips bulletin.

The only photos I'm aware of showing steel rim failure was the ralley style rims on one of the Chrysler France race cars in 1970 or 71 IIRC. It used to be on the web, but the website changed. Basically as Mitch described. My recollection was it looked like a single center. Depending on which FIA Group the car was in, a stock rim may have been required.

There is definately a point where lower weight is slower due to flex (specificly road racing where I know a shop that tested this) And of course some lightweigt rims may not flex much but will start to fracture. Got to finish to win a race...

Both the shape and material of the rim construction will determine potential to flex or fail under a given load.

Watch Bullitt.

"I'm curious if anyone here selects their rims for stiffness, and if so are steelies any less stiff than alloys? "

Its a good not yet well answered question, IMO. We seem to bend over backwards to reduce deflection elsewhere, when there is almost zero data to justify or quantify the problem elsewhere in our suspensions, my favorites are 11/16" TR and LCA bottom gusset plates. At a Ron Sutton track toy day long seminar in Ohio last year I attended, there was at one point he a panel of experts/vendors spoke about various pertinent suspension items, that included a wheel manufacturer. They stated wheel deflection is real and an issue, but not in their wheels. I asked them, and this point dovetails with another pissing match thread on this forum, how does brake induced heat effect the stiffness of their alum wheels, since at 200-300F alum loses a considerable amount of its strength compared to steel, and would say a heat barrier coating be advised to retain this stiffness they first mentioned?. They scratched their heads. Bottom line, if an alum wheel is flexing, it will be only a matter of time before it cracks. I do believe however elevated temps, lessons that propensity to crack.

Edit, if the amount of bending does not increase, but if the load is the same, the strength will be less, the bending amount will increase, and cracking issues return.

Check out the Motor Trend You Tube channel, the "Ignition" and "Head to Head" shows have some pretty potent cars on track and the way the tire/wheel(s) move around under extreme loads is eye opening.

When my son was autocrossing his '67 Barracuda we encountered this problem. The car was initially built retaining small bolt pattern and Kelsey-Hayes discs up front. When we started running Nascar slicks we had to make up some 15x10 small bolt rims. After a few events he was out on a run when we heard a rotational grinding/clicking. One center had cracked, but not at a lug.

At that point in time we swapped to big bolt and picked up two Pete Paulsen circle track 15x10s with custom offset. We took two of the small bolt wheels and swapped centers with some 14" rallye centers. Never had another wheel problem. We still have the Paulsen rims, but sold the others.

I watched first 9? mins of a 16 min video Mustang vs Camaro Head to Head. Not sure what I am looking for. I see tire deflection but this not the topic here. Don't see how with the naked eye I could observe any wheel deflection on a street driven car that wiuld mean much, and I saw none. If you have a specific video/time frame to indicate something, post it.

i remember watching a series of clips from a camera mounted under a car for a nascar race on a track such as dover, when under car cameras first appeared on the scene. it was focused on the front suspension and brake area, and i was amazed at the amount of movement the various components exhibited, including both tires and wheels. i don't know if this would be a relative example, but maybe worth viewing ? the time frame may have been with rusty wallace commentating when he first started in the booth, but i can't really recall exactly when this may have been.

I have cast aluminum wheels that are maybe 1/16" away from the calipers and they have never so much as scuffed.

Porsche 911 Turbo with 600+ HP and -3.5 camber F and R and needs to hit 1.5 G or better. HRE or Champion aluminum wheels, not cheap but light and strong. I would say the next down the line behind billet wheels are the ones that are spun when they are cast.

I love black wheels.
They look so much better than any other finish.
It is also more difficult to see micro cracks when the aluminum spokes develop them from track days.

Don't buy black wheels
haha!