'40 Olds need tires, Bias or Radial, Thoughts?

[SHGrace]

I have a 1940 Olds 70 Series that needs tires. The car has been in storage around 15 years and the previous set which appeared to go back to the 60's finally gave out. I'm looking at Firestone Blackwall 6.50-16 tube type from Coker. Before I pull the trigger I'd welcome thoughts on bias ply vs. radial.

Thank you in advance,

Seth

[Bloo]

In 16" you no longer have any reasonable choices in modern tires and it was never good.

 

16" modern tires you can still buy are way too wide for their height to even mount right and not hit stuff usually. That, or so low that they lower the gearing of a prewar car that is probably already geared too low for today's roads.

 

So in 16" radials, that leaves "bias look" radials from Coker and Diamondback. They're more expensive than bias. They almost look right, too. I like radials. I'd go for the Diamondback "Auburn".

 

Or you can get bias. I wrestle with this every time I buy tires. Bias is correct, and looks correct, and while the Diamondback and Coker radials look very close, there is nothing quite like the real thing. Bias don't drive as well as radials though. I also remember the days when both radial and bias were still on daily drivers, and bias caused a lot more trouble. They wore out quicker too. I typically want the bias for the perfect look, but buy the radials because I like the way they drive and I don't want to screw with tire trouble.

 

You won't get a definitive answer. This is like PC vs Mac, or Coke vs Pepsi, Vi vs Emacs... Everyone has a favorite. This will go on for pages, and be split right down the middle.

 

Welcome to the forum! Show us a picture of your Olds sometime. We like pictures!

 

Edited November 1, 2022 by Bloo (see edit history)

[SHGrace]

Thanks Bloo,

I should have been more clear. The radials I was considering were the "bias look" that you referred to from Coker.

No success loading photos.

 

 

[61polara]

Radial tires will generally make your steering heaver a slow speeds.  I don't know if this is true of the bias look radials, but it's something to consider.

[EmTee]

I put new Firestone 7.00-15 bias ply tires from Lucas on my '38 Century this year.  So far I'm happy with them (~1500 miles so far).  They ride and handle well (though radials would probably ride better yet...).  In any case, they look right on the car and it performs as I imagine it would have originally.

 

Edited October 25, 2022 by EmTee
added picture (see edit history)

[60FlatTop]

I put my third set of Coker biased tires on my '60 Electra this Spring. I have had older cars with biased tires as well. I have never found a shortcoming.

 

Radials just look wrong to me. Even the ones masked with a square shoulder have concessions in their aspect ratio that are a little off,

 

I have been driving my car an average of 1,500 miles per year since I bought it in 2001. Roughly 30,000 miles on the first two sets of four.

 

Be wary if you do go with radials. They could hide some needed repairs on an 80 year old car.

 

And you know you have started a long string of opinion related comments with this topic. It will surely be entertaining. You forgot to add that you might "upgrade" to a dual master cylinder.

 

[jrbartlett]

Running Coker radials on my '35 Auburn. Won't go back to bias ply on the car.

[edinmass]

I can give a bunch of reasons to not use radials. As a purist, and pain in the ass, I only run bias tires on everything pre 1965. When I see radials on a car……I immediately think to myself 🤮. Many to most people use radials to cover up issues…….Not all, but most. I understand the appeal of them. I don’t install fuel injection, electronic ignition, air conditioning, and a host of other items. It’s a slippery slope.

Edited October 25, 2022 by edinmass (see edit history)

[Steve Moskowitz]

Seth, I am not sure what your intended use is for the car and the type of driving you would do but having owned several Oldsmobiles including a 40 I am biased towards bias!  For the driving I did, at the time which was local and touring the cars performed just fine with the bias tires.  Just one opinion and you will find this is a debate that no one will ever win. My cars did not spend time on major highways at high speeds so I enjoyed the authentic feel of the way the car was from day one.  I have a 1975 Olds that was horrible on the highway and radials solved the problem but the 75 was a car I wanted to drive long distances with and the radials provided better handling for me.  

[Pete O]

I can never understand the guys who buy an antique car and then do everything they can to make it drive like a modern car.     

[Bloo]

29 minutes ago, Pete O said:

I can never understand the guys who buy an antique car and then do everything they can to make it drive like a modern car.     

Me neither, but I'm not sure it applies. Tires are consumables like gas, oil, spark plugs, fan belts, etc. You can just change them at the next interval if you don't like them.

 

5 hours ago, 61polara said:

Radial tires will generally make your steering heaver a slow speeds.  I don't know if this is true of the bias look radials, but it's something to consider.

I don't know either. It follows that it could be true because radials have more grip. I have heard this often and thought that it might be because people are stuffing modern sizes on, and they are so much wider that it is hard to steer. Maybe it wouldn't be true in an apples-to-apples comparison? It is definitely true if you add 2 or three inches of tread width. When I put radials on the 36 Pontiac, I meant to make a side by side comparison. These modern radials I have are tall and skinny like the original bias, but are now discontinued so won't help the original poster. On the day changed them I forgot. I wish I had got a side-by-side comparison. I will say that the slow speed steering is not obviously heavy. You do need to be moving a little for easy steering, just like with the bias tires.

 

Radials do need more pressure than bias. That is pretty important if you want them to live long. Too little air would definitely make the steering hard, and there are probably some people out there who don't know and are still using the original pressure specs that were intended for bias tires.

 

[avgwarhawk]

7 hours ago, EmTee said:

I put new Firestone 7.00-15 bias ply tires from Lucas on my '38 Century this year.  So far I'm happy with them (~1500 miles so far).  They ride and handle well (though radials would probably ride better yet...).  In any case, they look right on the car and it performs as I imagine it would have originally.

 

Was this picture taken at the AACA all car show at the AACA library this summer?

[avgwarhawk]

I recommend the bias ply for the following reasons:

 

1. They look right.

2. They provide the driving experience these old cars offer.

3. They are less expensive than radials.

4. It does not matter they wear out faster than radials.  You'll only drive 2000 miles or less a year. Sunny days. No snow. Maybe a cloud burst drive.  I driven in the rain on my bias.  No issues with traction. 

5. Did I mention they look right...

 

 

I run Coker Classic on my 60. Universal bias on my 54.  

Edited October 26, 2022 by avgwarhawk (see edit history)

[avgwarhawk]

3 hours ago, Pete O said:

I can never understand the guys who buy an antique car and then do everything they can to make it drive like a modern car.     

I'm with you. 

[EmTee]

1 hour ago, avgwarhawk said:

Was this picture taken at the AACA all car show at the AACA library this summer?

No, that picture was taken at a local cruise-in earlier this summer.  I haven't taken it to a judged AACA or BCA event yet.  I did, however, drive in the 76th AAA Revival Glidden Tour last month.

 

Edited October 25, 2022 by EmTee (see edit history)

[EmTee]

1 hour ago, avgwarhawk said:

I driven in the rain on my bias.  No issues with traction. 

Ditto.

[SHGrace]

Thanks for the comments guys. I will be ordering the Firestone bias tires from Coker. This car will not see a lot of miles. My intention is to maintain as much originality as I can. So far it's pretty much the way I remember it for the last 60 years.

By the way photos of the car are posted in the "Our Cars & Restoration Projects" forum under 1940 Olds 70 Series

[drhach]

What "issues" do radials cover up? 

[Bloo]

Loose parts and bad alignment. Sometimes they will make a car with a worn out front end drive WAY better. They don't try to dart all over the road like bias ply tires do, and that can mask all sorts of problems.

 

Don't fall into that trap. Fix any loose steering parts and adjust the steering box. Get the alignment checked. A worn out front end will still not do whats needed on that bad day when you need to make a really sudden move to avoid an accident. No matter how much the tires have lulled you into thinking it's fine, a loose front end is a loose front end. Another issue is that sometimes you can chew up and ruin a couple of brand new front tires in a few days without realizing anything is wrong with the steering. They sure do drive nice, but they don't save you from fixing the car.

 

[60FlatTop]

Radials will absorb much of the wear or deterioration in suspension components. Some bushes can be worn oval, some can be tight and inflexible. On cars with rubber body mounts the harshness of crushed mounts or loose mounts will be absorbed.

 

Years ago I used to hear owners say "I took the 35 year old biased tires off my car and put on a new set of radials. The car never handles so well!" I don't hear that one so often these days.

 

Radials became popular on full sized American cars in the early 1970's. It took some re-engineering to get the belts to stop slipping. There were a lot of very nice riding cars all through the 1960's that handled well enough to get premium prices equiped with biased tires. Not many Fleetwoods, Electras, or Town Cars would have left the showrooms if they handled as bad as hearsay implies.

[Ben Bruce aka First Born]

 

 Contrarian here.     

    If looking original is what one wants and price is no object, by all means go AFTER MARKET bias.  Personally I am not paying double or more for that.  And I REMEMBER when bias was the only thing. And tubes.  No thank you. 

 

  Ben

[Shootey]

33 minutes ago, Ben Bruce aka First Born said:

 Contrarian here.     

    If looking original is what one wants and price is no object, by all means go AFTER MARKET bias.  Personally I am not paying double or more for that.  And I REMEMBER when bias was the only thing. And tubes.  No thank you. 

Can I infer that you don’t use tubes in radials?  What year rims were designed for tubeless?  Can earlier rims safely go without tubes? Rims designed for tubeless have a ridge that prevents the tire from popping off. 

[F&J]

59 minutes ago, Shootey said:

Rims designed for tubeless have a ridge that prevents the tire from popping off.

VW bugs still used the older rim style without the bead locks when they first went to tubeless tires.  Later part of 1960s, around 1966, VW did start using bead locks.   

 

 

[Bloo]

I don't use tubes in radials unless it is absolutely necessary. A tire dissipates heat better without the tube. There's far less chance of tire failure without the tube. The rim ridges are nice to have but not absolutely required. A standard drop-center rim with no ridges shouldn't be a problem. Some rims can't reasonably be expected to hold air though, like the ones used on wire wheels where the spokes protrude through the rim. When tubes are used, they do need to be tubes rated for radial tires.

 

[Ben Bruce aka First Born]

4 hours ago, Shootey said:

Can I infer that you don’t use tubes in radials?  What year rims were designed for tubeless?  Can earlier rims safely go without tubes? Rims designed for tubeless have a ridge that prevents the tire from popping off. 

Shootey, I am using original 1950 wheels.

  I don't recall the need for 'new" wheels when tubeless and radials first became available,  and, yes, I was there.

 

  Ben

Edited October 27, 2022 by Ben Bruce aka First Born (see edit history)

[60FlatTop]

I drive my '60 Electra the most. I have original size, style, and whitewall width with absolutely no other justification than "That's what I want". In 20 years and 30,000 miles my average cost for the Coker's has been about $25 per tire per year.

 

I grew up swinging around a Coates Tireman manual tire machine and remember those safety beads showing up at our end of the market. In the early years it seems MOPAR was the most common user. There was a mix on the 15" rims. By the time most of the industry went to 14" they all had them for cars.

 

Tubes were common. Breaking down an 8.20 X 15 Double Eagle with a safety tube. Some rims reversed the wide side of the bead and they were a bear. Luckily we had the pneumatic bead breaker but even then the 14" were hard to break down.

 

Years ago I read a couple of books about the brain by a British psychologist who start the description of learn by rolling a BB down the surface of an inclined cookie pan. Then he put some grey goo on the surface and the BB made a groove in the goo that it always gravitated to. I liked that book and have never been able to find it again. My BB's have embedded paths in that hardened goo and the path just ain't going to change. And I feel comfort in knowing it has been explained. So it is biased tires for me.

 

Anyone remember that author. I'd love to find those books. I think it was a series.

[jrbartlett]

Radials are far more stable on worn roads with groves in the pavement. That was a big selling point in the 1970s when radials were first seriously penetrating the U.S. market. They also advertised more miles of tire life. I found both to be true then, and true now. The '35 Auburn that I refer to has everything rebuilt on the front end -- springs, shocks, rubber parts, wheel bearings, brakes, steering box & knuckles. Not covering up anything.  

[avgwarhawk]

38 minutes ago, jrbartlett said:

Radials are far more stable on worn roads with groves in the pavement. That was a big selling point in the 1970s when radials were first seriously penetrating the U.S. market. They also advertised more miles of tire life. I found both to be true then, and true now. The '35 Auburn that I refer to has everything rebuilt on the front end -- springs, shocks, rubber parts, wheel bearings, brakes, steering box & knuckles. Not covering up anything.  

I concur. Radials are far superior. However, the experience of the old car on bias is lost with radials. I can state that not all bias are made alike. There is a noticeable difference between Coker Classics on my 60 and Universal on my 54.  

[Ben Bruce aka First Born]

 

 This will never be resolved to the satisfaction of all.   As well it should not, since we are not clones.  PRAISE THE LORD!

 

  OP asked for thoughts. He has them. Now he can choose .

 

    Bernie, I have driven my 1950   21,000 miles in 14.5 years.   I had 12 years and about 20000 miles when the first set of firestone radials were replaced.  Those were just over $80. per in 2008.  Replacements were just under $100. per in 2020.  

Per tire after 12 years was about $8.33.       Per mile was about $0.02 .  Per tire about $0.005.

 

  Just the way I have always figured.  

 

  Ben

[Robert G. Smits]

I have had Diamondback radials on the 41 Cadillac for 12 years and 15 K miles.  If I am missing the bias driving experience I haven't noticed it.

[JACK M]

On 10/27/2022 at 12:16 PM, Ben Bruce aka First Born said:

Shootey, I am using original 1950 wheels.

  I don't recall the need for 'new" wheels when tubeless and radials first became available,  and, yes, I was there.

 

  Ben

I tried radials on original 65 Chrysler wheels. It had full wheel covers that would make noise and eventually fall off.

I was there as well and when I put radials non my 67 GMC daily driver van it was like getting a new rig. It had small hub caps.

[Doctor's Pontiac]

On 10/25/2022 at 1:15 PM, Bloo said:

Me neither, but I'm not sure it applies. Tires are consumables like gas, oil, spark plugs, fan belts, etc. You can just change them at the next interval if you don't like them.

 

I don't know either. It follows that it could be true because radials have more grip. I have heard this often and thought that it might be because people are stuffing modern sizes on, and they are so much wider that it is hard to steer. Maybe it wouldn't be true in an apples-to-apples comparison? It is definitely true if you add 2 or three inches of tread width. When I put radials on the 36 Pontiac, I meant to make a side by side comparison. These modern radials I have are tall and skinny like the original bias, but are now discontinued so won't help the original poster. On the day changed them I forgot. I wish I had got a side-by-side comparison. I will say that the slow speed steering is not obviously heavy. You do need to be moving a little for easy steering, just like with the bias tires.

 

Radials do need more pressure than bias. That is pretty important if you want them to live long. Too little air would definitely make the steering hard, and there are probably some people out there who don't know and are still using the original pressure specs that were intended for bias tires.

 

After months of delay blamed on Covid and supply chain problems, I received my Coker tires, bias-ply-like radials, 16.5 x 16, same size as factory and also with a set of recommended inner tubes. Today I went to a tire shop and spent some time observing the manager as he removed my 4 old bias ply tires and mounted the new radial ones. He was kind enough to let me take pictures of the process for the "apples-to-apples comparison" Bloo refers to. It is a busy shop so I had to shoot pictures when I had a chance but no time to stop him and delay his work for careful measurements to report here, which would be ideal.

 

My observations:

 

1. The Coker tires are actually a bit narrower than the old bias ply tires, just the opposite of what was commented here before. There was no difference at all in effort to turn the steering wheel

 

2. The Coker tires look taller. I did a crude quick measurement and is almost 1 inch total. However, they arrived much flattened and perhaps will become wider and shorter after placed on the car.  The beads from both sides were literally touching each other after removing the wrap placed for shipment and required a lot of force to separate them to apply some powder before mounting on the wheel.  

 

 

Radial on the L and old bias ply tire on the right. Both are mounted on the rim already for this photo

 

 

Radial on the L and bias ply tire on the R. The slight height difference is observable

 

3. Next photo shows the Radial already installed on the passenger side while the bias ply still on the driver side. Hard to see because of the light in the background but both, the tech and myself, could clearly see that the radial was a bit taller and closer to the floor

 

 

 

4. We dropped the car to the floor to check clearances and there was plenty of space between tire and fender and proceeded to mount the other 3 tires.

 

5. Coker sells these tires as same size of the originals. The next 2 photos show the size as written on the sidewalls.  is  Is the height difference important?

 

 

 

 

I drove home and decided to test on the Interstate, at 60 mph there was a dramatic improvement compared with my old tires, that appeared as an undecided voter, one moment pulled to the L and next moment pulled to the right and felt so unsafe to the point that I drove no faster than 45 MPH. May be the old tires would be better if they had been balanced. We saw no weights on the rim for balancing them. 

 

These are the first bias looking radials I have and they look close to stock but drive much better so I am happy with this decision.

 

Manuel

 

 

Edited November 1, 2022 by Doctor's Pontiac
Typos (see edit history)

[Bloo]

Height affects gearing, but what really matters is the radius, distance from the center of the wheel to the ground when rolling. There could conceivably be more difference with the weight on or off and rolling on a radial.

 

In any event, the little difference you see there isn't going to be a big deal. Original bias ply tires sometimes varied wildly from what they are marked.

 

The aspect ratio on a pre-65 tire size is either 90% or 100%. I suspect 100% is correct for 650:16. Making that assumption, 16 + 6.5 + 6.5 = 29" tall.

 

I just went and looked at the specs on some currently available 650:16 bias plies.

 

Firestone        29.1

Garfield          29.26

BF Goodrich   29.3

Goodyear       29.41

Coker             29.26

Lester             29.25

 

Coker's radial 650-R-16 claims 29.26 inches. I think you might be closer now than you were before.

 

Edited November 1, 2022 by Bloo (see edit history)

[NailheadBob]

@Doctor's Pontiac was there a dip in road when your car pulled left and then to right? Radials are very sensitive toe in/out adjustment, and I have experienced that happening, possibly something to check?

 

Bob

[Doctor's Pontiac]

1 hour ago, NailheadBob said:

@Doctor's Pontiac was there a dip in road when your car pulled left and then to right? Radials are very sensitive toe in/out adjustment, and I have experienced that happening, possibly something to check?

 

Bob

It happened constantly on concrete paved road, the type found on Interstate freeways, with numerous parallel grooves on the surface that seem to pull the wheels all the time to one side or the other and created a very wobbly and unstable control of the car at a speed above 45 MPH. The problem happened only with the old bias ply tires and is totally gone now with the new bias looking radials. I am having an alignment this week and will also check the toe in/out adjustment as you suggest.

 

I wanted the original poster to have this information considering that we have nearly same cars.

[J.H.Boland]

I replaced the original 9.50/16.5 bias nylons (the morning thump never seemed to go away) with a set of 8.75 16R radials. That old '72 Chevy 3/4 ton went from riding like a dump truck to a Buick ! 

Two years ago, I replaced the ancient 6.50/16 Cokers on the '40 Packard with comparable radials. I'm very satisfied with them. It isn't a show car, just a nice driver.

[NailheadBob]

1 hour ago, Doctor's Pontiac said:

It happened constantly on concrete paved road, the type found on Interstate freeways, with numerous parallel grooves on the surface that seem to pull the wheels all the time to one side or the other and created a very wobbly and unstable control of the car at a speed above 45 MPH. The problem happened only with the old bias ply tires and is totally gone now with the new bias looking radials. I am having an alignment this week and will also check the toe in/out adjustment as you suggest.

 

I wanted the original poster to have this information considering that we have nearly same cars.

Got it,

 

My bad, I misunderstood, I thought the pull happened with the radial tires, sorry for my confusion.

 

Bob

[Doctor's Pontiac]

On 10/31/2022 at 8:05 PM, Bloo said:

Height affects gearing, but what really matters is the radius, distance from the center of the wheel to the ground when rolling….

 

The aspect ratio on a pre-65 tire size is either 90% or 100%. I suspect 100% is correct for 650:16. Making that assumption, 16 + 6.5 + 6.5 = 29" tall.

 

I just went and looked at the specs on some currently available 650:16 bias plies.

 

Firestone        29.1

Garfield          29.26

BF Goodrich   29.3

Goodyear       29.41

Coker             29.26

Lester             29.25

 

Coker's radial 650-R-16 claims 29.26 inches. I think you might be closer now than you were before.

 

I obtained this measurement with tire inflated to 34 lb psi and used a ruler on top of tire trying to keep it horizontal. I got 29” which falls within expected value. So the Coker bias ply looking radials 650-R-16 have the correct size.