Tires , radial vs. bias ply, for factory wheels
 

Hello, I am interested in learning what pros and cons each type of tire offer for the early torsion bar equipped trucks in particular, and all the 1/2 ton trucks in general. And also assuming factory wheels being used.

Re: Tires , radial vs. bias ply, for factory wheels
 

Hello, For a baseline, I have included a picture of the factory wheel/tire combo from a 1960 GMC 1002 Custom Wideside 1/2 ton truck. They appear to be Firestone Bias ply tires. Does anyone have any time in riding on these tires? I am also including a picture of the wheels I am running. They are 15 inch wheels. I am running Radial Whitewall right now. I believe they are contributing (at least somewhat) to excessive sway in curves. I wonder if I can lose the swaying without going to bias ply tires. I love the ride, till I have to turn, then its in Gods hands.
Have any of you guys had good service out of your tires? Let me know. Thanks, Greg Mead

Re: Tires , radial vs. bias ply, for factory wheels
 

Here is the wheel tire combo I am running. It is a factory wheel with a 40,000 mile rated tire that has the whitewall vulcanized onto it by an outfit in South Carolina.

Re: Tires , radial vs. bias ply, for factory wheels
 

Well, I have been pleased with my Goodyear Traction Hi-Milers. They are a bias ply tire and closely resemble tires from the time when our trucks were built. Not idea how they are rated for wear or traction, but they are considered a trailer tire.

Re: Tires , radial vs. bias ply, for factory wheels
 

OK Greg . Before it gets to far off the rails lets talk about how you use your truck. First you have a heavy high powered top heavy rig most likely riding on tires designed to give a smooth ride on a 3000 lb vehicle. Any full size 60-87 GM truck will suffer from poor performance in the curves with a P rated 225 or 235 70 or 75. 15 inch tire. To counter act that somewhat a Lt rated tire in the same sizes will give better performance due to its heavier side wall and higher load capability. Theses tires still give a look that is more stock. A lot of the sway you are experiencing is really the tires deflecting under the lateral load. your outside front wheel in the curve is pushing down a couple of inches closer to the ground . The best way to get better performance in a tire is to use a tire designed for more aggessive driving. These would be something like a BFG. Radial TA in 225-60-15 . However these don't give a stock look. And they really need a 6 or 7 inch wheel. The best compromise I have found is a Lt rated 225-75-15 with 35 psi. It looks stock and performes ok.

Re: Tires , radial vs. bias ply, for factory wheels
 

Excellent synopsis, Barry, I am considering changing tires. The choices I have in mind are the LT's you mentioned, and the factory Firestone Champions produced by Coker, in the original molds. They offer true blackwall, as I assume they all shipped with, and whitewall. I have also been trying to learn the correct size for my factory wheels. They make a 6.7-15 and a 7.10-15. I have uploaded a picture of the tire sizes from 1960 GMC literature. It shows a 7.10-15 as standard. I have 15 inch factory wheels. Is there an upgrade or just plain better size for my tires than the 7.10-15? I see some a 4 ply and others 6 ply rated. Is that a factor for a light truck like mine? Are bias ply tires hard to get used to coming from a life spent on radials? The tread patch looks rather narrow. Maybe my mileage will go up a little. They look cool, and I guess you could say they are correct, but I wonder did they ship any trucks with the whitewall version in 1960. They sure pushed the whitewalls in there ad material, almost exclusively. Any advice appreciated, Greg Mead

Re: Tires , radial vs. bias ply, for factory wheels
 

I don't know if this is the best place, but you might find my experience useful. My 1964 GMC 1500 came with 15 inch two-piece wheels that required use of tubes. I understand that you want to keep your truck original, and I held out with the 15 inch wheels and bias ply tires for many years, but I finally gave in when the local tire dealer became less inclined to work on my wheels and most pickup trucks were running on radials. My switch was to LT235/85R16 M+S load range D Radials, which required getting new one-piece wheels. I have never regretted it. The bias ply tires would track in grooves and occasionally would "jump" to the left or right without really changing direction. This was not from pulling because of poor alignment. The ride was stiff, and the tires would develop flat spots (especially when cold) that took several minutes to roll out. All of this went away with the switch to radials. Handling and ride greatly improved, I am getting more miles from the tires, there is much more to choose from, and the new tires are a little taller which slightly reduces engine rpm while providing a few more mph on the open road.

However, there was an unanticipated problem. I measured to be sure a new spare tire would not be too wide to fit in the space under the bed, but forgot to check on depth. As usual, what I didn't check turned out not fitting. It only took a longer piece of threaded rod to accommodate the bigger tire, but this is something to keep in mind.

Good luck with your choice of wheels and tires. Personally, I like the radials.

JRMunn