Lack of availability - reproduction tires

[Joe in Canada]

If you need tires in the near future I would check if they will still be available. I have been waiting 2 years coming December for Lester 700-19  at $482 a tire. Was told today that the Lester will be discontinuing that line after this run of tires are produced when ever that is. The Firestone 700-19 tire at $755 each for the wide white walls and will still be available. I canceled my order and now getting Firestone for if I need a replacement in the future they will still be available. 

Do some availability checking on your line of tires before you buy.

Just a heads up as times they are a changing.  

[TAKerry]

Not just tires. 

[TAKerry]

I will elaborate a bit. I have been working on a special edition trans am for the last 5 yrs or so. The appearance is heavily dependent on a certain stripe package. Rather expensive at well over $500. I figured when I was at the point I would order them. Not quite ready but getting close, I found out through the grape vine that they are no longer available. Seller said not much call for them. Few cars were made and nobody in their right mind would restore one. No idea if and when they will be available. These were for pre molded I was able to get it in rolls and even those are on a limited basis.

SO, its just not tires, even cars from the 70's may have a hard time finding stuff. Sign of the times.

[Matt Harwood]

Joe, are you sure you need double whitewalls at $755 each? The single whitewalls are considerably less at $512.

 

These numbers are WAY up over the prices of even just a year ago. If anyone needs tires, I'd take Joe's advice and get them NOW. I'm sure they're only going to get harder to find and more expensive from here.

[nat]

     I don't know what it costs to get them across the border but both Lucas and Universal offer several choices in that size  from $328 to $755 USD for the double whitewall Firestone.  $512 for Firestone single whitewall.

[tcslr]

Joe,

What car are these going on?  I'd have thought your Cadillac is 17 or 18s.  Hope the family is well.  Tom

[Joe in Canada]

Thankyou Mat I was under the impression it was a wider white wall not a double. Getting old and making mistakes. Thanks again.  

Hi Tom my car is a 1930 so it has 19 in. rims where 1931 rim size drops to 18 in. rims. Hope all well with your family also and hope to see you on tour next year.

nat never mind customs try the Fedex cost. 

[Joe in Canada]

With the pre war cars being driven less I would thing even more tire lines will be less available as sales drop. Everything depends on quantity.

[1935Packard]

11 minutes ago, Joe in Canada said:

With the pre war cars being driven less I would thing even more tire lines will be less available as sales drop. Everything depends on quantity.

Certainly possible.  I wonder if pre-war tire purchases have for a while been based more on tires getting old and becoming unsafe and needing replacement rather than being used so much that they need replacing.  But maybe cars are being used so little that owners are just stretching out the number of years between tire replacements. 

[marcapra]

On my 48 DeSoto restoration, I'm coming to the point of driving it very soon.  It has some around 50 year old tires on it, but the car has been sitting for the last 43 years.  Obviously, I'm going to want some new tires.  The original size of these tires are 7.60 X 15" bias ply.  I think I will follow your advice and look for new tires now.  I know there is a debate about going with bias ply or radials.  What are the pros and cons?  I have also seen there are radial tires meant to look like bias ply.  I want black wall tires as I have the white beauty rings for my wheels, and they don't look good with white walls.  Does anyone have a manufacturer they could recommend?  

[Dave Wells]

36 minutes ago, 1935Packard said:

...maybe cars are being used so little that owners are just stretching out the number of years between tire replacements. 

I seem to be driving my old cars less and less every year and never much further than to a cars and coffee get together, a local show in the park, or for ice cream when the grandkids come to visit. I stretch out tire life as much as I can. If they are pliable, have no dryness or cracks, and hold pressure, I feel pretty safe in driving them around town at 25 to 35 mph. I've experienced both high speed and low speed blow-outs in the past and lived to tell about them. I have spare tires on all the vehicles and would be able to change a flat if and when it might occur - and AAA is just a phone call away. I think my last flat tire was in 1987, and that was at freeway speed with a relatively new tire. I certainly wouldn't trust a really old tire like marcapra (above) has on his car, but when I'm looking at hundreds of dollars per tire, I tend to take the most conservative route I safely can.

[Reynard]

23 minutes ago, marcapra said:

 I know there is a debate about going with bias ply or radials.  What are the pros and cons?  I have also seen there are radial tires meant to look like bias ply.  I want black wall tires as I have the white beauty rings for my wheels, and they don't look good with white walls.  Does anyone have a manufacturer they could recommend?

I'm not qualified to recommend bias or radials, one over the other, for cars of the '40's or '50's. However I do know that the ride and handling of my '60's cars improved when I switched to radials.

In addition, the price on radials is more favorable, in my experience, than new bias ply tires. New radials that look like bias ply tires tend to be more expensive yet.

I, and other owners of older cars I have talked to, have found that (don't laugh) Amazon offers good quality radials in a variety of sizes. One in particular that might fit your car is this 195/75r/16 that is only fractionally different from the 600/650x16syou probably have. The current price is just under $120. each and includes free shipping.

White walls and inch walls in other sizes are available, too.

 

https://www.amazon.com/Nexen-Roadian-Commercial-Radial-Tire-195/dp/B01MSL0LSB/ref=sr_1_1?crid=1WRDAXERC7QQ0&keywords=195%2F75r%2F16+car+tire&qid=1701329255&s=automotive&sprefix=195%2F75r%2F16+car+tire%2Cautomotive%2C244&sr=1-1&ufe=app_do%3Aamzn1.fos.17d9e15d-4e43-4581-b373-0e5c1a776d5d

 

Nexen Roadian CT8 HL All- Season Radial Tire-195/75R16C 105R

[marcapra]

Actually, my car had 7.60 x 15" tires and were called Super Cushion back then.  I'm not sure if they were Goodyear or Goodrich.  I'm thinking of going with bias ply if they have one in blackwall.  But when I look up bias ply tires of this size, I usually get trailer tires.  Or I may go with Coker American Classics that are radials made to look like bias ply with a cost of $390 each.  I don't plan to drive my car long distances or in the rain, so bias ply might make sense if they still make them.  

[marcapra]

After looking for 7.60X15 tires in bias ply blackwall, I didn't find any.  So I may have to get a radial tire made to look like a bias ply.  This is the only one I found in my car's size:  https://www.cokertire.com/tires/american-classic-760r15-blackwall.html

[edinmass]

 

I have been posting about the lack of availibility of tires for three years now.....I stock extra tires for all my cars because you can be holding nothing in your hand for years at a time. Tubes are the same way also.......

[Bloo]

How badly do you need it to say 7..60-15 on the sidewall? Tire manufacturers did not always hit the theoretical size exactly. Also molds for reproduction tires tend to be molds that still exist. The marked size might be off by a lot, and as I recall, large 15s are some of the worst offenders. Check the section width and the overall diameter. Coker/Firestone 7.10 looks real close to a theoretical 7.60 to me for instance.

[West Peterson]

47 minutes ago, Bloo said:

Tire manufacturers did not always hit the theoretical size exactly ... molds for reproduction tires tend to be molds that still exist. The marked size might be off by a lot.

^^^

True that. You may want a 6.00, but the tire was made in a 6.50 mold with just the size number changed. You may want a 7.00 tire, but the tire was made in a 6.50 mold with just the size number changed. So there you have three different size tires made in one mold. This becomes a problem if your car originally had the smaller size, as the larger tire will not fit inside the metal spare tire covers.

 

In regard to bias ply vs radial. You don't have to replace bias ply tires as often as radials, so for me, if a car was never available with radials, I would stick with the bias ply. If you're not concerned with how the car looks AND you drive it a LOT at highway speeds, go with radials if you want. If you only drive your car 2,000 miles a year, it's a lot less expensive in the long run to go with bias ply, not to mention a lot less hassle.

 

I feel fortunate in finding a set of BRAND NEW Firestone 6.50x19s at Hershey this year, bought from a consumer who changed his mind on what size wheel he was using on his restoration. I paid his asking price and got the whole set for $500. 

[West Peterson]

On 11/29/2023 at 8:27 AM, TAKerry said:

Not just tires. 

^^^

True that, too. I just ordered a battery, and was told anywhere from 5 to 9 months.

[marcapra]

If I buy whitewalls, can I just mount them on backwards so the blackwall shows, or paint out the white wall?  I didn't know that I could buy a different size tire than 7.60X15.  So 7.10 or 7.00 would work on my rims that were meant for Super Cushion tires?  My rims are 5.5" wide.  I guess a 6.70 would be too thin as they were meant for a 4.5" rim.  

[Dave Wells]

15 minutes ago, marcapra said:

If I buy whitewalls, can I just mount them on backwards so the blackwall shows, or paint out the white wall?  I didn't know that I could buy a different size tire than 7.60X15.  So 7.10 or 7.00 would work on my rims that were meant for Super Cushion tires?  My rims are 5.5" wide.  I guess a 6.70 would be too thin as they were meant for a 4.5" rim.  

I think you need to research the subject more thoroughly - wheels, tires, radial vs. bias, etc. It sounds to me like you may be throwing away money needlessly, especially when you consider "...buylng whitewalls, ... mounting them on backwards so the blackwall shows, or painting out the white wall".

Are you restoring your car to #1 show condition or will it be a Sunday driver? Who is going to be looking at the size or type of tires on your car? As long as they fit the wheels and fenders correctly and look close to stock (if that is your objective), you can stay away from the collector tire vendors and have a safe and reliable set of tires for a fraction of the price.

Check other websites and discussion groups; talk to other old car collectors and drivers in your area; join a related vintage car club, even a national Mopar group. I would even drop in to local tire shops and see what they and their professional resources recommend for your situation.

Personally, I think spending nearly $400. per tire ($1600 per set of four -or $2000 including the spare) is ridiculous. There's no need for such an expense for a good-weather driver, a '48 DeSoto, as nice as it may be.

 

[Bloo]

  

2 hours ago, marcapra said:

If I buy whitewalls, can I just mount them on backwards so the blackwall shows, or paint out the white wall?  I didn't know that I could buy a different size tire than 7.60X15.  So 7.10 or 7.00 would work on my rims that were meant for Super Cushion tires?  My rims are 5.5" wide.  I guess a 6.70 would be too thin as they were meant for a 4.5" rim.  

 

Width and height is complicated. If I completely understood exactly what happened in the period your DeSoto was made I would explain it. I might have some hints though.

 

Any 15" tire will theoretically go on there, some will be too wide, but within reason you can substitute. Know this though, modern tires are almost always too wide compared to height. It is easy to follow some substitution table and wind up with something that is too wide to go on the rims, or that hits everywhere. If you go narrow enough, the diameter will be too small and leave the engine revving higher, speedometer wrong, etc. "75" series is as good as it gets, and it often isn't good enough. I know you weren't looking at modern, but bear with me for a minute. Understanding those new sizes helps understanding the old ones... err... sort of. Take 205/75R14 for instance. 205mm is the widest spot on the tire, when mounted on whatever rim size they designed the tire on. 75 is the aspect ratio, expressed as a percentage. 75% of 205mm is 153.75mm. 153.75mm is the height of the sidewall down to the bottom of the bead. Convert that to inches (divide by 25.4) and you have 6.05. Take that number twice, once for the top part of the sidewall and once for the bottom, add the rim width, and you have the tire height. 6.05 + 6.05 + 14 = 26.1 inches tall. Then like now, the manufacturers rarely hit it exact, and you have to look in their spec sheets if you want exact numbers. Still, it will be sort of close.

 

For what it is worth, when there is no aspect ratio on a metric tire (155-R-15 or something), assume 80%.

 

Ok, so you see how this aspect ratio stuff is done. In the beginning, lets say 1901 or so, and if you were making some steam cylinder to push a buggylike thing around, all you cared about was the outside diameter so you could multiply by 3.14 and know how far the wheel would roll in a revolution, and how to gear up your buggy. There were no tires to buy because there were no cars. At first tires were hard buggy tires, and when pneumatic tires came along the casings were round, and there was no tread. Aspect ratio was not considered at all, nor was there any reason for anyone to think of it. You could just assume the marked size was the height as well as the width. There are some problems with this. Take a 34x4 tire for instance, as used on a few cars in the mid teens. 34" is the outer diameter, and 4" is the width. Aspect ratio is 100%. The rim size is not specified. 34 - 4 - 4 = 26 inches, so those tires go on a 26 inch rim. 34x4-1/2 on the other hand goes on a 25 inch rim. 34 - 4-1/2 - 4-1/2 = 25 inches. Rim size is never obvious. You have to calculate. Also, by the mid teens tires with tread were becoming popular. Casings were still round, so when you pile some tread rubber on top of a round casing and the aspect ratio could easily be 110%. The idea of using outer diameter for the size probably made sense in 1901. By 1918, not so much.

 

A few years later, by the 20s, they started putting fatter "balloon" tires on cars and specifying rim diameter. Aspect ratio was still probably not considered, and still 100%, but closer to 110% in practice because of thick tread. There were some sizes that might be specified the old way, and maybe the new way from another manufacturer or bought a different year. For instance 30x5 and 500-20 would be exactly the same size tire. That brings us ALMOST to your DeSoto. Common tire sizes of the late prewar and early postwar era are like that, 600-16, 650-16, 700-16, 700-15, etc. These tires have a 100% aspect ratio and are probably more like 110% in practice.

 

****Warning: Wild speculation follows ****

 

Something happened in 1948. I have seen references to this, but never any solid information. This is how I think it was though, based on something similar that happened in 1965. This is completely wild speculation so take it with about 10 grains of salt. Sizes introduced in 1948 or later had about a 90% aspect ratio. They also had width numbers that were not exact quarters or halves (575, 600, 650, 700, etc.). I'm talking about sizes like 6.70-15, 7.10-15, 7.60-15 and so on. Instead of an aspect ratio of 100% that was 110% in practice, these new sizes would have an aspect ratio that was 90%, and more like 95% or a little more in practice. The old sizes, at least some of them, continued production. This is why 700-15 and 7.10-15 are not nearly as similar as you would expect.

 

****

 

In 1965, the system changed again. New sizes ended in 5 (like 7.75-14), and were a lower aspect ratio, probably 80 percent. This is not speculation. I have a poster buried somewhere dated 1965 from one of the major tire companies explaining it. It tells you what new sizes to substitute for the old. Since these are lower profile tires, 80% aspect ratio or so, the new numbers are always bigger, and the tires a little fatter to achieve the same height. There were 2 or 3 exceptions on the chart. I do not recall what they were.

 

So now you know. It's confusing as hell, and reproduction tires cover all three periods of time (and more). The manufacturers probably never hit the numbers exact in the first place, and in reproductions sometimes the size of the tires needed and the size of the still existing molds don't quite match. Still, with the information above you can probably look at the advertised width and diameter of repro tires, add it up and figure out what to expect. Also you can see why I thought that Coker's repro Firestone 7.10-15 is so close to 7.60-15. I didn't check any other possibilities. There might be some.

 

A final example, in purely theoretical numbers for some similar looking sizes in 3 different systems. Look at the radical difference in height :

 

750-15 (introduced pre-1948)   aspect ratio 110%(100%)  7.5 inches wide, 8.25 + 8.25 + 15 = 31.5 inches tall

7.60-15 (introduced 1948-1964 period)   aspect ratio 95%(90%)  7.6 inches wide, 7.2 + 7.2 + 15 = 29.4 inches tall

7.75-15 (introduced 1965 or later)  aspect ratio 80%  7.75 inches wide  6.2 + 6.2 + 15 = 27.4 inches tall

 

 

 

Edited December 1, 2023 by Bloo (see edit history)

[7th Son]

50 minutes ago, Bloo said:

  

 

Width and height is complicated. If I completely understood exactly what happened in the period your DeSoto was made I would explain it. I might have some hints though.

 

Any 15" tire will theoretically go on there, some will be too wide, but within reason you can substitute. Know this though, modern tires are almost always too wide compared to height. It is easy to follow some substitution table and wind up with some that is too wide to go on the rims, or that hits everywhere. If you go narrow enough, the diameter will be too little and the engine revving higher, speedometer wrong, etc. "75" series is as good as it gets, and it often isn't good enough. I know you weren't looking at modern, but bear with me for a minute. Understanding those new sizes helps understanding the old ones... err... sort of. Take 205/75R14 for instance. 205mm is the widest spot on the tire, when mounted on whatever rim size they designed the tire on. 75 is the aspect ratio, expressed as a percentage. 75% of 205mm is 153.75mm. 153.75mm is the height of the sidewall down to the bottom of the bead. Convert that to inches (divide by 25.4) and you have 6.05. Take that number twice, once for the top part of the sidewall and once for the bottom, add the rim width, and you have the tire height. 6.05 + 6.05 + 14 = 26.1 inches tall. Then like now, the manufacturers rarely hit it exact, and you have to look in their spec sheets if you want exact numbers. Still, it will be sort of close.

 

For what it is worth, when there is no aspect ratio on a metric tire (155-R-15 or something), assume 80%.

 

Ok, so you see how this aspect ratio stuff is done. In the beginning, lets say 1901 or so, and if you were making some steam cylinder to push a buggylike thing around, all you cared about was the outside diameter so you could multiply by 3.14 and know how far the wheel would roll in a revolution, and how to gear up your buggy. There were no tires to buy because there were no cars. At first tires were hard buggy tires, and when pneumatic tires came along the casings were round, and there was no tread. Aspect ratio was not considered at all, nor was there any reason for anyone to think of it. You could just assume the marked size was the height as well as the width. There are some problems with this. Take a 34x4 tire for instance, as used on a few cars in the mid teens. 34" is the outer diameter, and 4" is the width. Aspect ratio is 100%. The rim size is not specified. 34 - 4 - 4 = 26 inches, so those tires go on a 26 inch rim. 34x4-1/2 on the other hand goes on a 25 inch rim. 34 - 4-1/2 - 4-1/2 = 25 inches. Rim size is never obvious. You have to calculate. Also, by the mid teens tires with tread were becoming popular. Casings were still round, so when you pile some tread rubber on top of a round casing and the aspect ratio could easily be 110%. The idea of using outer diameter for the size probably made sense in 1901. By 1918, not so much.

 

A few years later, by the 20s, they started putting fatter "balloon" tires on cars and specifying rim diameter. Aspect ratio was still probably not considered, and still 100%, but closer to 110% in practice because of thick tread. There were some sizes that might be specified the old way, and maybe the new way from another manufacturer or bought a different year. For instance 30x5 and 500-20 would be exactly the same size tire. That brings us ALMOST to your DeSoto. Common tire sizes of the late prewar and early postwar era are like that, 600-16, 650-16, 700-16, 700-15, etc. These tires have a 100% aspect ratio and are probably more like 110% in practice.

 

****Warning: Wild speculation follows ****

 

Something happened in 1948. I have seen references to this, but never any solid information. This is how I think it was though, based on something similar that happened in 1965. This is completely wild speculation so take it with about 10 grains of salt. Sizes introduced in 1948 or later had about a 90% aspect ratio. They also had width numbers that were not exact quarters or halves (575, 600, 650, 700, etc.). I'm talking about sizes like 6.70-15, 7.10-15, 7.60-15 and so on. Instead of an aspect ratio of 100% that was 110% in practice, these new sizes would have an aspect ratio that was 90%, and more like 95% or a little more in practice. The old sizes, at least some of them, continued production. This is why 700-15 and 7.10-15 are not nearly as similar as you would expect.

 

****

 

In 1965, the system changed again. New sizes ended in 5 (like 7.75-14), and were a lower aspect ratio, probably 80 percent. This is not speculation. I have a poster buried somewhere dated 1965 from one of the major tire companies explaining it. It tells you what new sizes to substitute for the old. Since these are lower profile tires, 80% aspect ratio or so, the new numbers are always bigger, and the tires a little fatter to achieve the same height. There were 2 or 3 exceptions on the chart. I do not recall what they were.

 

So now you know. It's confusing as hell, and reproduction tires cover all three periods of time (and more). The manufacturers probably never hit the numbers exact in the first place, and in reproductions sometimes the size of the tires needed and the size of the still existing molds don't quite match. Still, with the information above you can probably look at the advertised width and diameter of repro tires, add it up and figure out what to expect. Also you can see why I thought that Coker's repro Firestone 7.10-15 is so close to 7.60-15. I didn't check any other possibilities. There might be some.

 

A final example, in purely theoretical numbers for some similar looking sizes in 3 different systems. Look at the radical difference in height :

 

750-15 (introduced pre-1948)   aspect ratio 110%(100%)  7.5 inches wide, 8.25 + 8.25 + 15 = 31.5 inches tall

7.60-15 (introduced 1948-1964 period)   aspect ratio 95%(90%)  7.6 inches wide, 7.2 + 7.2 + 15 = 29.4 inches tall

7.75-15 (introduced 1965 or later)  aspect ratio 80%  7.75 inches wide  6.2 + 6.2 + 15 = 27.4 inches tall

 

 

 

 

 

Gotcha...

 

Now in the Old Days...

 

 

 

 

 

 

Edited December 1, 2023 by 7th Son (see edit history)

[marcapra]

I think I found my tire.  I never realized that Coker still made the Goodyear Super Cushion 7.60 X 15 tires that my car came with when it was new in 1948.  I am seriously considering getting four of them if they're available.  They have the wide white walls, but maybe i'll take the beauty rings off and go with whitewalls.  

[marcapra]

Now there a glitch in my choices.  A friend of mine who used to own a 38 DeSoto said when he bought a set of radial tires, it improved the ride and handling of the car so much it was "jaw-dropping!".  But he did admit that his old bias ply tires were almost worn out.  And I heard from another who bought bias ply tires, that he wished he bought radials.  I really want the original tires, but the radials sound much better.  I guess I'll wait until I can drive my DeSoto to see how much I like my bias plys, but they about 50 years old and have been sitting for decades!  

[Bloo]

Diamondback Auburn Deluxe 700R15 hits fairly close to your 860-15 at 29.4 inches tall, and about 0.4" wider at 8 inches wide, if you have room for almost an extra 1/2" of width. Blackwall or whitewall. 710R15 (29.2/8.2) and 820r15 (27.9/7.8) also exist.

 

https://dbtires.com/

 

 

[Dave Wells]

1 hour ago, marcapra said:

Now there a glitch in my choices.  A friend of mine who used to own a 38 DeSoto said when he bought a set of radial tires, it improved the ride and handling of the car so much it was "jaw-dropping!".  But he did admit that his old bias ply tires were almost worn out.  And I heard from another who bought bias ply tires, that he wished he bought radials.  I really want the original tires, but the radials sound much better.  I guess I'll wait until I can drive my DeSoto to see how much I like my bias plys, but they about 50 years old and have been sitting for decades!  

 

Might as well be driving on these tires:

Even if you make it around the block, it still won't be a fair comparison between bias and radial.

[Bloo]

I always wind up with radials. They go straight naturally, and in my experience cause less trouble.

 

[EmTee]

FWIW, I have no complaints regarding the reproduction 7.00-15 Firestone whitewalls I bought for my '38 Buick two years ago.  My only regret is not having bought a 5th one for the spare.  I may do that in the near future, just in case... 

[TAKerry]

Can someone please post some pictures of a bias ply tire beside a radial? I hear so many times 'the car looks fine except for the radial tires'. Do they really look that different? Or is it just a bias against radials? 

[Dr B]

 

10 hours ago, marcapra said:

I guess I'll wait until I can drive my DeSoto to see how much I like my bias plys, but they about 50 years old and have been sitting for decades!  

Are you suggesting you are going to drive around on 50 year old tires?! I hope not.  First, it will not give you any indication how your car will drive on bias-ply tires (how it will drive on rock hard rubber maybe, but not actual tires!).  Second, I would be concerned they will fail leading to potential damage to your car and or to you!

 

As for Diamondback tires, I can wholeheartedly recommend them.  I switched from bias to db radials a few years ago on a '59 Corvette and the change in the drive is dramatic and they look correct.  

 

Robert

[Matt Harwood]

I put radials on my '41 Buick which originally wore 7.50-16 bias-ply and now wears 750R16 radials. Diameter and width are comparable. The reproduction radials that look like bias-plys are even better--these are Hercules truck radials.

 

 

 

[edinmass]

I’m not a radial fan on any car pre 1965. That said, I understand why people do it. Remember, going

from bias to radial requires a different alignment. Almost no one bothers. 

Edited December 2, 2023 by edinmass (see edit history)

[TAKerry]

Thank you Matt, Im still not quite sure what Im looking at but in the picture showing the 2 tires side by side with the tread showing, it looks to me like the tire on the left is a modern radial? the other a bias ply?

[Stude Light]

5 hours ago, TAKerry said:

Can someone please post some pictures of a bias ply tire beside a radial? I hear so many times 'the car looks fine except for the radial tires'. Do they really look that different? Or is it just a bias against radials? 

These are the bias ply tires I took off my 1939 LaSalle

This is the Diamondback Auburn Radial I put on

Very similar look and tread pattern. They run at 45 psi so you don't get the "radial bulge" at the ground contact patch. This also reduces the higher rim loading that is typical from a radial due to less flexing of the tire at the patch.  Better ride, better handling, better wet road traction and no tubes. I set the car to factory alignment specifications and it tracks down the road - hands off the wheel.

 

The downside is that the rims were designed for bias ply which spreads the load from the tire flexing at the contact patch to more of the rim. The radials will impart higher loads on the rim as the load is more centralized at the contact patch but, as mentioned, the higher pressures do help to reduce that load some, however, you still become the wheel test engineer. Being an engineer myself, I did talk to one of my wheel engineer cohorts when I made the switch and we looked at some loading numbers....I'm not concerned but I do check my wheels for cracks each season.

Scott

[3macboys]

11 hours ago, TAKerry said:

Can someone please post some pictures of a bias ply tire beside a radial? I hear so many times 'the car looks fine except for the radial tires'. Do they really look that different? Or is it just a bias against radials? 

Kerry, my poor drawing is an exaggeration but from what I've seen the bias ply tend to curve in from the sidewall to the tread, and radials tend to round over from the tread to the sidewall.  My sketch is a cross section of what I'm trying to describe with the bias ply on the left and radial on the right.  Of course tires are like the English language with a lot of most of the time but not always "rules"  .  My apologies to Walt G in advance for my artistic skills, but I'm still trying all these years later!

[ramair]

Hi all, question, I have a 1939 Packard twelve that the previous owner put diamond backs whitewalls ( wow in one sentence both Ed and AJ have their hair bristling for different reasons) anyway I was told that the tires were proper size for the car.  The car drove great which could be the Packard twin flex independent suspension or because the car weighs 5,500# or radials? The owners manual calls for 8.25”X 16”, so I called Diamond back and they said they only make a tire equivalent to 7:50 X 16” and according the salesman they never made anything else.  My theory is that my tires were truck tire that they ground off the printing on the sidewall and attached a white wall over that.  Can anyone shed light on this? 

[Bloo]

All Diamondback whitewalls are indeed put on after the fact, as far as I know. They have tires of their own design (Auburn Deluxe) as well as preexisting tires from other manufacturers. I think any 16s you bought today would be theirs. I doubt truck radials exist to modify. Maybe, but most if not all 16s have disappeared. If they are a few years old it is possible. The Auburn Deluxe was vaporware for several years, and only 600R16 when it first dropped. There were off the shelf 16s available back then.

 

EDIT: 825-16 I have never heard of before either, but I would expect it to be about 8-1/4" wide and 34.2 inches tall. Wow. That's enormous. I suspect you will have to settle for the biggest tallest 16s you can find, and they still won't quite measure up.

 

Edited December 3, 2023 by Bloo (see edit history)

[Bloo]

15 hours ago, TAKerry said:

Can someone please post some pictures of a bias ply tire beside a radial? I hear so many times 'the car looks fine except for the radial tires'. Do they really look that different? Or is it just a bias against radials? 

 

A little of both I think. 40 years ago they usually had a visible bulge at the bottom of the tire. I had not noticed it in years, and suspected it was all due to people using insufficient air pressure (radials need more). Then, one of our own forum members decided he didn't like the way his looked. He posted pictures (Coker American Classic Radial If I remember correctly) and there it was, the radial bulge. His tires were not underinflated. I didn't think it looked that bad, but it was definitely there, and definitely noticeable. He switched back to bias. Look for it though. Every modern car in a parking lot will have radials. How many bulge? You sure don't see it much anymore.

 

Another thing that triggers comments like that is typical 75 series modern tires when mounted on antiques. The aspect ratio is just wrong and it looks weird on the older ones. Sometimes they fit the rims OK, sometimes they don't. The smaller diameter will screw up the speedometer a little, and change the gearing for the worse. On some cars that matters, on others it doesn't. I have no problem with it. On the bright side, modern tread probably stops better. Tires are consumables. If I don't like them, I'll get different ones next time. Modern 75 series tires do look funny, but they are radial and they are cheaper, so they have that going for them. Your mileage may vary.

 

Edited December 3, 2023 by Bloo (see edit history)

[Gary56]

Can anybody tell what size tires I need to replace my tires.  They are 8.125 x 19

[Larry Schramm]

1 minute ago, Gary56 said:

Can anybody tell what size tires I need to replace my tires.  They are 8.125 x 19

 

How about giving us a hint on the make, model, and year of the vehicle you are talking about?