Regarding use of radial tires on older rims

[bamfordsgarage]

I saw this today on another forum — good information on tire construction, rim stress, and potential problems from the use of radial tires on rims designed for bias-ply tires.

http://www.sema.org/files/attachments/WTC-2011-05-Bias-vs-Radial-Tire-Wheel-Fitment.pdf

[Frank Elder]

Blank page for me.

[Don Coatney]

Not blank for me. Main reasons I opted to not use 60+ year old rims on my car with radial tires.

Here are the closing statments in the article.

Summary - What you should take away from this explanation is that:

• The tire industry makes radial and bias tires that can be mounted on the same rims.

• Not all wheels and rims were designed for radial tires

• Construction features of radial and bias tires make them bulge differently when deflected

• The radial’s localized bulge puts more stress on the rim flange than a bias tire does

• Rim fatigue and cracking can happen to any wheel from normal flexing, cyclic loading, and cornering

• Radial stressing of the rim can accelerate metal fatigue and rim failure that is uncommon with bias tires.

• Failures will usually occur where wheel materials change direction (e.g., flange to bead seat, bead seat to

well, well or base to wheel center, etc.).

• Evidence of cracking may be visually obvious or it may be indicated by air leakage.

Recommendations

1. Remember that not all rims are suitable for new technology radial tires.

2. A radial application checklist for vintage cars should include:

- Are my wheels a pre-1975, primarily bias design?

- Did my wheels come from the factory with radials?

- If my rims are old, do I know how to look for cracking issues?

- Should I replace my wheels with newer, radial compatible items?

3. If in doubt about your rims’ ability to endure radial tires….consider only bias tires

4. If radials are applied, check your wheels often for possible cracking

5. Use qualified technicians to mount, service, and inspect your wheels and tires

[Young Ed]

That seems like a much more intelligent approach to it than the blanket statements of no radials on old rims.

[Greg F]

Starting to think about purchasing some wide white walls for my P-15. Is there another rim I can exchange for the 16" wheels that came with the car, so that I can install radial tires without tubes?

Thanks Greg

[Captain Neon]

At the risk of being the old curmudgeon, SEMA is an acronym for Specialty Equipment and Marketing Association. Despite all of the good things they do, one must not forget that they are an organisation that's primary purpose is to sell new parts, accessories, and equipment. While having the best of intentions, it is SEMA's basic premise that new is better than old.

After almost 12 years, and over 20K miles with radials on my original 16" rims, I will not hesitate to put radial tyres on any post-war rim in good repair.

Despite the numerous cars using radial tyres on original rims, if one is still nervous about having radial tyres on vintage rims, they should probably use modern rims.

[Eneto-55]

Someone will remember the name of the process - it escapes me right now - but one possible approach to feel more confident would be to take your rims (probably need to be bare steel) to a plating shop that does aircraft repair, and have them check for hairline fractures. It's something with a black light, I think. Sorry I can't remember what it's called.

Neto

[Mark D]

Magnaflux?

[TodFitch]

Magnaflux?

That is one test, works for materials like cast iron that are affected by magnetism. I think that for things like aluminum they use a dye penetration technique for crack detection.

[BobT-47P15]

I used some radials on my 15" 1955 Chrysler wire wheels......with no

problems. I did, however, use radial tubes in them since I don't know

how airtight the rims are. Have since replaced them with bias ply

wide whites which look good, but don't handle as well as the radials.

[Eneto-55]

Mark & Todd,

Yeah, MagnaFlux. That's what I was trying to remember. I wasn't involved in that end of the work - I worked in plating, but saw them doing this on propellers all the time. Maybe there are two different processes that I have sort of combined in my memory.

Neto

[greg g]

Remember folks, Chyrsler was the first major manufacturer to introduce safety bead rims. These wheels incorporated the retaining ridge that is still the feature of modern steel wheels. So I would be inclined to think this would be a positive point to the consideration of running contemporary radials on older rims. Also European cars have been running radials on similar rims since the late 40's. Think of all the Volvo, Saabs, and Little British cars that had skinny steel and wire wheels and mounted Michelin and other brands of radial ply tires.

I thin the main considerations would be the condition of your wheels, and the width of the tire. Remember we were dealing with a skinny tire with a tall sidewall. The early radials although metric in measurments were still skinny and tall. I remember 165/15 was a popular size. Today's tires with their lower aspect ratios, and shorter sidewalls might put more strain on the bead area than the older style tall and skinny radial.

I have chosen to run 75 series radials (there still might be some 80's out there but scarce) but I decided my rims were too rusty i the bead area and went to after market wheels to be on the safe side. Even still at 5 inch width, they don;t want a real wide tread width, so I might be pushing things with the 225's I run on the rear.

Probably not a big deal for lightly loaded cars, going on a gentle trip on the back roads to the ice cream stand, but for the miles I drive I wanted decent modern tires on new rims.

[Plymouthy Adams]

another point is that I really do not see the average owner of one of these cars careening around at breakneck speed, asphlt melting burnouts and drifting...you would call it a great day if you got behind one of these cars and it was running the speedlimit..!

[austinsailor]

I think I'm going to write up a paper and post it on the internet. If it's there, it has to be true, right?

I've had a couple wheels crack over the years, none with a radial tire mounted on it.

If this were accurate and a concern, along about the mid to late '70s we would have seen a rash of wheel failures. I worked in a station with a tire shop in the back that sold a lot of BF Goodrich radials, almost all mounted on wheels that originally had bias tires on them. I did the tire repairs for a year. I never saw a failed wheel with a radial tire on it. The only failed wheels I saw were a couple that were rusted so that they cracked along the outer lip where the tire mounted. None were a catastrophic failure, they were flats where the crack was noticed while it was dismounted.

I did see catastrophic failures of tires - I recall one guy where I had to round up another spare. He drove over a broken Pepsi bottle which took out a 3" dia plug from both his front and rear tire. I saw blowouts where radials had lost the whole sidewall, dropping them straight to the ground. I saw sidewalls cut clean through where they hit a curb - but in all cases the wheels were intact.

If you have wheels that were severely rusted at one time, I'd be worried a bit. Deep pitting, bent and straightened I might take a closer look. By the way, there is a whole industry doing this from the back of trailers - they have to leave a wheel weaker than they found it and I haven't heard of them being a problem.

I think this is a lot of smoke with no substance. If you're going to worry, I'd be a lot more concerned with the extra stresses put on the front end parts by the extra traction of the radials.

[greg g]

Hmmmmmm... did he say drifting????

not unheard of

and burn outs

[Young Ed]

My 46 pickup has original 16s that I got out of a junkyard. They have some pitting but were sandblasted and painted. I put 215 85 r16s on them over 10 years ago. Haven't had any issues yet. I also hauled 1200lbs of dirt in the bed twice last summer and no issues.

[TodFitch]

It might be nice to get Coker Tire to chime in on this as they are now selling radial tires in sizes where you can't buy a modern rim. For example, they offer one that fits on the skinny 17" rim used on my '33. Seems like they think radials are safe for older rims. Or maybe their radials are different in some way but they don't say that in their descriptions. They also sell it in sizes appropriate for Model A Fords but you can get new wheels for those. Noticed that they have some in the 165/15 size greg g wrote were popular when radials first came out.

[Plymouthy Adams]

I am sure in the fine print liability is with the end user..

[JIPJOBXX]

Anyone want a set of used radial tires on 15" rims for $100? All mounted and ready to go! Contact oft line if you want them.

[Captain Neon]

I think I'm going to write up a paper and post it on the internet. If it's there, it has to be true, right?

I've had a couple wheels crack over the years, none with a radial tire mounted on it.

If this were accurate and a concern, along about the mid to late '70s we would have seen a rash of wheel failures. I worked in a station with a tire shop in the back that sold a lot of BF Goodrich radials, almost all mounted on wheels that originally had bias tires on them. I did the tire repairs for a year. I never saw a failed wheel with a radial tire on it. The only failed wheels I saw were a couple that were rusted so that they cracked along the outer lip where the tire mounted. None were a catastrophic failure, they were flats where the crack was noticed while it was dismounted.

I did see catastrophic failures of tires - I recall one guy where I had to round up another spare. He drove over a broken Pepsi bottle which took out a 3" dia plug from both his front and rear tire. I saw blowouts where radials had lost the whole sidewall, dropping them straight to the ground. I saw sidewalls cut clean through where they hit a curb - but in all cases the wheels were intact.

If you have wheels that were severely rusted at one time, I'd be worried a bit. Deep pitting, bent and straightened I might take a closer look. By the way, there is a whole industry doing this from the back of trailers - they have to leave a wheel weaker than they found it and I haven't heard of them being a problem.

I think this is a lot of smoke with no substance. If you're going to worry, I'd be a lot more concerned with the extra stresses put on the front end parts by the extra traction of the radials.

Were this facebook, I would click the "like" option on this post. I have a hard time believing that I am some how a lucky outlier flirting with disaster, esp. since I know lots of people that switched to radials in the '80s. I have yet to hear any of them regretting the decision, only lamenting the discontinuation affordable wide white wall radial tyres.

[1941Rick]

One would think that if there was a danger in running radials on bias rims the tire shops would not put them on. Afterall there would be a danger of the rim blowing during inflation. Tire shops are getting more and more concerned about Liability. here in Canada they are not wanting to instal just 2 winter tires. They insist on 4 for safety. I am running radial on my 41 and the only problem I have come across is where the valve stem comes thru the rim. For tube type the hole is oval and the tubeless stem is loose in the rim.

[Plymouthy Adams]

Rick..you not using the special oval style valve stems in your wheels?

[55 Fargo]

Anyone want a set of used radial tires on 15" rims for $100? All mounted and ready to go! Contact oft line if you want them.

Jonny, you be the opportunist of the thread.........LOL

[1941Rick]

No..is there such a thing?

[greg g]

Yep try a truck parts place. Also most auto parts places stock 2 piece screw on valves that will address the oval hole deal.