Packard Forum Index » General

I have run radials on my 51 200 for at least 10 years with no problems. One of my friends here insists that the older wheels were not designed for the load of radial tires and that the wheel can actually break when radials are mounted. He is more familiar with Hudsons and said that he knew of about three instances where the wheel broke while being driven. Does anyone have any adverse experience with wheel failure?

Also, when changing from bias ply to radial, has the steering effort gone up or down? (Assuming that your car doesn't have power steering)

thanks

I think we have been over this jump, but I can't find it.

I remember this as something that had some basis in fact (the rims were changed some for radials) but which in practice is rarely a problem.

Can anyone confirm or refute this?

I suggest that it is an urban myth. There are many out there, including myself, with Coker radial tyres requiring around 40 PSI minimum inflation pressure Versus the old 24-32 PSI factory settings. I have never heard of a Packard rim separating. I also believe that the internal pressure loading on the rim from 40 PSI would be the same for a cross-ply as for a radial. I do however use a tube in my Packard wheels, even the 56, which I understand is supposed to OK for tubeless. I have Commercial 10 PLY 17in radials on my 35 Super wire wheels which I run at 55PSI. If it was going to blow, I suggest that it would have by now. I must add that I have split rims on my 35 Super so we are not talking of the original rims, although I believe that the rim has been made from the original Packard rims. I have split both rear axle wire wheels fitted with cross-ply tyres on my 1934 Plymouth after hitting a table drain in a country town in 1968, whilst towing a car trailer with a 526 Packard aboard home. My opinion is that you can damage anything if you try hard enough. Best Regards Peter Toet

I'll have to agree with Peter Packard.

I've been running radials on my 56 Exec for over 10 years and more than 20K miles. Just installed a new set. No problems.

IF (and that's a big "IF") there was going to be any rim splitting problems thaen one would most likely experience wheel cover/hub cap loss FIRST. AND experience it on a frequent basis before any splitting.

Possibly some of the LOW PRICED models of cars (with in same make) prior to the HP revolution of 1955 mite have had some very thin lite duty wheels. WHICH MEANS that the higher priced models had heavier wheels. But such lower priced models would have been considered lite duty or utility grade to begin with and maybe only 45 mph cars. I've ran into this much to my surprise on pre '55 JEeps. But the old 4 cyl 40's and early 50's jeeps were 45 mph vehicles at best.
But no wheel splitting.
Claims of wheel splitting and suspensions not "tuned " for radials are weak claims at best without SPECIFIC reasons for the claim.

Without regard to "wheel spliting";

The radial tends to have less rolling resistence so the foot print of the radial does not move rearward as far as the bias ply. That tends to simulate more positive caster.

However, most cars prior to the wide spread popularity of power steering (ca. 1960's to 1970's or go try to buy a car 1980 and later withOUT PS) ran negative caster (PS or no PS). Neg caster (historic trend)= less effort at steering wheel but high road compliance (ok for lower speeds). Pos caster (modern trend) = harder steering effort at steering wheel but less road compliance = streight steady steering.

So the radial mite tend to create a bit more effort at the steering wheel (u'll never notice it with PS) but streighter tracking of the car.

I looked into this once and supposedly the bias rim is not the same. However, these tire companies specify sky high tires pressures for antique radials which probably is intended to compensate. Modern car tire pressures are around 8-10 psi higher than the old bias ply; typically in the 32 psi range

Last weekend I was driving around Washington DC and I'm glad I don't over inflate my tires because the roads are moonlike. The ride quality with proper tire pressure is affected with even a few pounds over.

I've read or heard of a number of instances over the years of rims fatiguing or splitting with radial tires. Whether the tires were the cause or not is uncertain, but in most every case the rims were on more lightly-built cars of the 50s, Studebaker and Chevrolet come to mind as those mentioned.

On page 37 of the latest 2013-14 Diamondback catalogdbtires.com/ there is an article addressing rim stress with radial vs bias tires. To me the arguments and points made seem factual and well thought out but then I'm not selling radial tires. There are some size conversion and load charts and a lot of other interesting info on tires in the back pages of the catalog.

THanks for the link HH56.
Owen Dyneto raises a good point in post #7 above.
Case in point, 1965 Chevies:

In 1965 go buy a NEW BOTTOM of the line FULL size chevy. IIRC Biscayne or maybe it was a DelRay. Got 14 inch very skimpy wheels and tyres. So skimpy the car looked like it was going down the road on 4 dimes.

SAME car, add a 283 V8 with a little ginger bread trim inside and out and call it a Caprice. It got 15" with IIRC F'stone wide Ovals or somekind of premium grade tyre. I don't think the radials were availble until about 1968 some 3 years later.

HOWEVER, BOTH cars got many sets of new tires thru out the cars life (say 20 years) as the tires wore out. Cars that originaly designed for bias belted and running thru late 70's early 80's got radials as replacements. NEver heard of any rim splitting on those.

The radial tire was not something that happened over nite. It was phase in during the late 60's thru early 80's. So any claims of rim splitting due to wheels designed only for bias belted is shallow at best since so many millions of vehicles (say 1950's thru 1980's vehicles) had tires replaced with radials when OEM was bias.

Isolated circumstances of wheel splitting would have probably happened anyway regardless of the tyre design.

Had a friend with a 58 Chevrolet. She installed radials and promptly began throwing wheel covers off into the weeds alongside the road. Later went back to bias ply and the wheel covers stayed put.