Steering: Bias versus Radial tires

[doubledaddy]

I just brought home a 50 champion and 50 land cruiser and have a question about tires. The LC has H78-15 tires and I do not know exactly what they are. Are they normal bias ply tires or something like radials? The car needs front end work. I am tracking down and purchasing parts and plan to rebuild it when I have all the parts. My question is, how will the H78's influence handling. I know with the present tires and mechanical condition it's almost impossible to keep it in one lane on the highway. I put a pair of 205-75 tires on the front and it made a big difference. Is this normal when going to radials with a car with a good front end?

The Champion has 195-75-15 tires and drives fairly good although it too needs quite a bit of work. I installed a set of Coker's 670-15 polyester bias tires I had laying around and it got pretty squirrely. I'm just wonder if these conditions will still be around with a new front end.

Sorry for being so long winded but I I have two sets of wide whitewall almost new tires I would like to use. But if they are going to be a problem I thought about selling them to help with parts cost.

[Cornbinder89]

So, you have likely 40 year old tires, and you want to know??? Rubber ages and most tire shops consider the life over at 6 years. Sure, I have some old tires on my farm truck but they will "chunk out" rather then roll over a rock or other obstruction.
Modern tire codes have an R in them if radial so HR 78 or 195R for example. Given that we went away from the Alpha-numeric system for tires in the 70's, I would guess your are at least that old.

[TWChamp]

In the late 60's and early 70's I drove my 1950 Commander between El Paso and Alamogordo on weekends with bias tires, and it drove straight and rode nice as can be. The 50 Champion I bought last summer came with new radials, and it also drives straight and rides nice. Either type should work well on your Stude, if the suspension and steering are good.

[StudeRich]

Your Land Cruiser Tires were 7.10X15 H78 replaced them in the 70's which should be replaced with P215X75R15 Radials.
The P205X75R15 size will work on your Champion.

If I owned an early 1950's Car like those, I would not fool with inferior, yesterday's quality repro Coker or whatever overly expensive Tires.

You can still get Cooper Trend Setter Radials (U.S. made & owned) in Narrow White Walls (Black stripe next to the Rim, used on '63-'66) in our sizes, that look just fine on any '47 to '66 Stude. for maybe half the price but with todays Technology not Yesterday's, and they drive very well.

Also, they will not look like "gangster" white walls with the white rolling onto the shoulders of the tire which is totally incorrect for 1956 to 1962 Wide Whites.

Pardon me, if your intent with these Cars was to trailer them to car Shows, I guessed that you might want to actually DRIVE them.

[t walgamuth]

The bias ply tires if the front end is tight and aligned properly will track straight on a perfectly smooth highway. If you hit any rain grooves the front end will move all over the place on Bias ply tires. I'd only put on radial tires on any car I own since if I own it it will be driven. Bias ply is fine for show only.

[rockne10]

I agree with Tom. Both bias and radial will track straight on smooth roads. But, as soon as the bias tire hits a milled road, lane change restrictions or a steel mesh bridge it is wanting to go wherever it wants.

[unclemiltie]

I normally run 28 pounds pressure on my bias tires. I still have them on a couple cars I do not drive out of the local area. The set on my 50 Commander are Allstate tires so I have no real clue how old they really are. My friend whom gave me the car bought them new I am guessing in the mid 70"s. these are true 4 ply tires with tubes. I realize I have to replace them if I ever put the car on the interstate. This car has always been garage kept and they have been out of the sunlight. I do believe the rubber in these has to be better than what we get today as they say current tires should be replace every 6-10 years.

[StudeRich]

Milt, I have no idea about the quality of the rubber Old vs Newer, but I am pretty sure that the sidewall construction and Bias Ply's is what allows the Bias Ply's to last for decades instead of 5-6 years.

You never saw a Bias Ply blow it's Tread off like radials very commonly do, unless it was a Retread.

In use, the constant flexing of the thin, usually 2 Ply. sidewalls does the radials in quite quickly.

It seems that quite often I go out to the "back 40' to pull some Parts from the Parts Cars, and find still another one just sitting on older tires, with a half worn Radial exploded by blowing it's Tread with the steel cords hanging out!

This is not Arizona, so I am sure high temps are not the cause, it rarely exceeds 70 Degrees here and pressures never are more than the recommended 35/36 PSI.

[bezhawk]

https://www.cokertire.com/

Coker now has radials that look exactly like the original bias ply tires. Pie crust edge tread pattern etc. This is the best of both worlds

[t walgamuth]

The bias ply tires do hold together for a long time. I used to have a 59 Ferrari which came to me with 20 year old bias ply tires. After I got it running I took it out to a deserted "test" road I knew about and had it over 110 mph several times without incident.

[Cornbinder89]

old rubber gets hard, it breaks rather then flex, it matters little if the tire construction is bias or radial. I have run 20-50 year old rubber, and seen the results, hit something and you'll be missing a chunk of rubber, often right down to the cords. For my "farm truck" that never exceeds 45 mph, and 10 miles from home, I'll take the chance, something that I run on the highway, not a chance.

[TWChamp]

Rich is right about the radials blowing. I've had 3 sets of Goodyear Regatta radials and all but one or two have had ply seperation and sidewall blowouts. These are always run with 32 pounds pressure and never over 60 MPH on my 1991 and 1999 Olds 88's.

I've run many old bias tires with no problems as long as the weather cracks don't reach the cords.

[Buzzard]

All early tires were made from mostly rubber, whereas the modern product comes mostly from the petrochemical industry. This is why modern tires dry rot (from the inside out which can't be seen) at a much faster rate than we were previously used to. See posts # 7 & 8. Coming from the tire industry for 40+ years, recently we received bulletins from Michelin, Bridgestone, Goodyear etc. that if we deem a tire to be older than 6 years, DO NOT PUT IT INTO SERVICE. This is their reasoning as the deterioration has already begun. I recently sold an International Scout which had tires with really good tread, and I advised the new owner to replace them anyway (due to date coding I determined the production date). He didn't get more than 20 miles until they came apart. This seems to be be the nature of newer rubber substitutions being used.
I advise to err on the side of caution and if a tire is 10 years or older, replace it rather than risking a wreck.
Bill

[doubledaddy]

Thanks everyone.
The tires I have are less then 6 years old, I don't think age is a problem. I also just learned something from the card inside the glove box door. The Champion says 6.40/15 tires with 26 psi fron and 22 psi rear and Land Cruiser says 7.40/15 with 24 psi front and 20 psi rear. I have always ran around 30 in most cars and had the bias as well as the radial I was experimenting with at 32 front and 30 rear. I think I need to do more research on this.


I was reading an article on the Lucas Tire site and there are a lot of opposing opinions on this subject, very confusing. It looks like with a good front suspension and steering bais tires will work fine with the one exception of trying to follow groves in the road.

[rkapteyn]

I have a set of bias ply white wall tires that I bought new from cooker 20 years ago.
There are tiny cracks in the sidewalls but the tires only have less than 1000 miles on them and look like new.
Can I install tubes in these and be safe?

Robert Kapteyn