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Den41Buick

Radial vs. Bias ply

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What is the consensus on the performance of radials on cars that were engineered for bias-ply? Any issues with radials? What are the favored choise of www radials. Thanks!

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If you plan to show a vehicle at an AACA national meet that did not come from the factory with radials, and they weren't offered as an option for that year/make/model, there is a three point deduction for all incorrect tires including spares. Just something to think about for show vehicles.

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I put a set of radials on my 63 Riviera and it does drive and handle better. It now has a tendency to lose hubcaps though, because the radials grip better and tend to make the rim flex when cornering.

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I put a set of radials on my 63 Riviera and it does drive and handle better. It now has a tendency to lose hubcaps though, because the radials grip better and tend to make the rim flex when cornering.

You just defined the reason that radial tires should not be placed on wheels/rims that were not designed for them. "Flexing" equals eventual metal fatigue and that is certainly not desirable for a wheel.

In the short term with a vehicle that is not driven that many miles a year it may never be an issue, but then no one wants to be humming along on a highway and all of a sudden be dealing with a wheel that fails thanks to flexing caused by radial tires. Unfortunately detecting the degree of metal fatigue taking place with a wheel is beyond looking while the car is parked.

Best to call Coker and buy a new set of wheels that are correct for the car and suitable for use with radial tires.

Jim

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I concur. I got tired of chasing hubcaps in construction zones. I bought wheels from Coker designed for radial tires and the constant squeaking disappeared and haven't lost a hubcap since.

Also, please check for ball joint clearance on your bias-ply tires. The cross-section of a radial can be much wider. The previous owner of my Mark II installed cheezy spacers to cover up the problemh. Not a great idea on a 5,300# car. I simply ordered wheels with a shallower backset, creating more clearance.

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You all just changed my mind. I've been wanting to put wide whitewall radials on my 50 Chrysler to improve the steering. Sounds like I might be buying problems.

Thanks, I sure do learn a lot here.:)

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Well, unless I'm willing to buy new wheels, which I'm not, I should stick with bias tires.

Also didn't realize there was a point reduction when judging.

I think radials would handle a little better, I did not realize they might stress my old wheels.

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Best to call Coker and buy a new set of wheels that are correct for the car and suitable for use with radial tires.

Jim

I've wondered about this since last summer when I noticed that Coker now has 550-17 radial tires that would fit my wheels. However, to the best of my knowledge you can't get an original looking new manufacture wire wheel for my car. Even the Coker web site does not seem to show that size wheel in any style for any make of car.

So what to do when my current tires wear out in the next couple of years?

Go with radials that might provide better wear and grip (braking) and worry about the original rims not being up to snuff? Or go with a period incorrect tread pattern on a bias ply that, if past experience is any guide, will wear out in less than 20,000 miles and probably require lots of weights to get anywhere near being balanced?

I can only say that I'm glad that I have a year or two to make up my mind on this. Maybe clarity will come.

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I've wondered about this since last summer when I noticed that Coker now has 550-17 radial tires that would fit my wheels. However, to the best of my knowledge you can't get an original looking new manufacture wire wheel for my car. Even the Coker web site does not seem to show that size wheel in any style for any make of car.

So what to do when my current tires wear out in the next couple of years?

Go with radials that might provide better wear and grip (braking) and worry about the original rims not being up to snuff? Or go with a period incorrect tread pattern on a bias ply that, if past experience is any guide, will wear out in less than 20,000 miles and probably require lots of weights to get anywhere near being balanced?

I can only say that I'm glad that I have a year or two to make up my mind on this. Maybe clarity will come.

Low mileage expectation is just part of the world of bias ply tires. The only bias ply tires that ever exceeded 12-15K miles before becoming dangerous from wear were the fiber glass belted tires of the very late 1960s. Also known as Polyglass.

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.....Also didn't realize there was a point reduction when judging. .....

Yes, that is the case. It is as if the vehicle is "sitting on blocks" with no spare(s) if radial tires are put on and they are not correct for the year, make and model they are on.

Some folks do buy the correct new wheels for radials and a set of radials for regular driving/touring, but have a set of correct wheels and bias ply tires for showing at AACA national meets to avoid the deduction issue. :)

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Yes, that is the case. It is as if the vehicle is "sitting on blocks" with no spare(s) if radial tires are put on and they are not correct for the year, make and model they are on.

Some folks do buy the correct new wheels for radials and a set of radials for regular driving/touring, but have a set of correct wheels and bias ply tires for showing at AACA national meets to avoid the deduction issue. :)

That gets passed both potential issues with wheel failures and judging, but it doesn't get passed the fact any tire which has become more than five years old is not safe on the road, maybe not even around the block, regardless of the number of miles they have been used. Just sayin'!

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That gets passed both potential issues with wheel failures and judging, but it doesn't get passed the fact any tire which has become more than five years old is not safe on the road, maybe not even around the block, regardless of the number of miles they have been used. Just sayin'!

Or so says the makers of tires....................Bob

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I also know the entire alignment has to be set up differently from spec to properly account for radials.

I have Coker bias ply reproduction Firestones on my '56 Vette and to be honest, I think it turns and handles just fine. I especially think it feels really smoothe too. It is what it is, and for what it is, it rides and handles more than fine with original style tires.

That said, if I was going to do some cross country touring, I would change the weels as mentioned, add the radials, and do the alignment changes. All just for the safety aspect if nothing else.

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That gets passed both potential issues with wheel failures and judging, but it doesn't get passed the fact any tire which has become more than five years old is not safe on the road, maybe not even around the block, regardless of the number of miles they have been used. Just sayin'!

True, but that is sort of a whole 'nother issue. :rolleyes::D

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Or so says the makers of tires....................Bob

And the DOT. Realistically, the tire makers and insurance companies don't want or need the legal cost involved when an accident has been determined to be from a tire failure.

Of course it is likely that many so called tire failures are resultant from vehicle owners failing to maintain proper tire inflation and/or to maintain their vehicle properly, which can lead to abnormal tire wear and failures. We can add to that vehicle owners arbitrarily deciding that having hit or run over something didn't damage a tire. We've all done that figuring if the tire was still holding air it was okay......Not necessarily!

Personally, it is not worth the potential risk of life for me to push the time envelope. I don't need to be dead or in the hospital over a darn tire, and I sure don't want to kill or hospitalize someone else over the cost of replacing a darn tire.

Jim

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And it pays to verify when the tires were manufactured. We had a tire fail on our 2002 RV, 2001 chassis as many times RV makes buy chassis in advance, last year on May 20th. We were very lucky that it was not a front tire that blew and that we were able to get the rig off of the interstate and into a local church parking lot where we could wait for help from our road service. And our friend Rodger Woodrum, another AACA member and judge, who lives a few minutes from the exit we were able to use.

What we found out was that the tires on it were made in April of 2000. That means that they had been on the chassis for two years before we bought the rig new in Charleston, S.C. So those tires sat out in the sun and weather for about a year and a half when we bought it on November 26th, 2001. Most of that time it was not moved as it sat to go through the plant to have the "coach" added and then sat on the lot to be sold.

We now have all new tires on it.:)

post-36313-143138477836_thumb.jpg

Edited by Shop Rat (see edit history)

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True, but that is sort of a whole 'nother issue. :rolleyes::D

Not really. We all tend to make monetary judgments at times that are a mistake. Maintaining two sets of tires with each having a limited shelf life probably tends to make people want to avoid replacing tires because of age simply because of cost. Obviously, taking points off in judging for radial tires being on a car manufactured before 1967 or thereabouts may tend to cause people to make bad decisions, that might just kill them or someone else.

Jim

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What I meant by that was that this was the original question.

"What is the consensus on the performance of radials on cars that were engineered for bias-ply? Any issues with radials? What are the favored choise of www radials. Thanks!"

And that age of the tires regarding replacement was "a whole 'nother issue". :)<!-- google_ad_section_end -->

But you are correct, many do not wish to spend what it takes to have both kinds of tires and wheels and to replace them as they should be as you suggest.

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Personally I'd like to see some impartial and definative strength and failure testing data vis-a-vis tire ageing before I'd start replacing tires every 5 years. A few years ago the safe age limit I'd hear bandied about was 7 years. The DOT and tire makers have a vested interest in getting everyone to s**t can perfectly good tires. They take the worst case scenario and apply it to everyone. It also gives the vested interests a legal loop hole to wiggle through should a tire fail after 5 years even though it may have been used gently and sparingly.

I have 6 collector cars, 2 everyday drivers and a trailer and I personally won't be s**t canning

36 perfectly good tires because someone says they are past thier "best if used by" date.

I've been driving for 55 years and the only explosive blowouts I've experianced were on two near new Carlisle 10 ply trailer tires. Both within thier weight range, properly inflated, below 65 MPH, on cool days. Go figure..............Bob

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Fact or not the "retire after 5 years" thing is one heck of a marketing strategy. Very little of the strength of a tire is in the rubber and usually those cracks are only a few millimeters deep. Can you imagine your Dad or Granddad scrapping a tire due to surface cracks after 5 years?

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My cars just don't look right without the aspect ratio of a biased tire. I have a 1960 Electra with 8.20 X 15's and a 1964 Riviera with 7.10 X 15's. Both cars had 78 series tires when I purchased them.

I like my cars looking the way they did when I first took interest in cars as a kid.

Both cars drive and handle very well, the Riviera has new springs and all new bushings, the Electra is a well maintained 72,000 mile car. Often when a friend is riding with me on our rough Main St. I fake the image radial tire promoters like to project. I pretend to fight the wheel and ask him to look at the sweat on my brow from fighting these terrible tires; then I just relax and lay one hand on the top of the wheel.

All the reading I have done about this debate can be summed up in one sentence," I replaced the 27 year old biased tires on my car with radials and, boy!, it handles like a dream."

I am buying a new set for the Electra next month. The current set of biased tires are worn out. I installed them in 2002 and have put 10,000 miles on them. Eight years would be an appropriate time to replace any tire, biased or radial.

Bernie

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Radials do not look right on a car built for bias plys. Wide whites do not look good in either case.

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