Bias and radials?

[TDW]

I need some wider tires for the rear. Looking for something like the Coker L60-15. They only come in bias. How bad would it be to run them with radials on the front? Looking for someones opinion who has actually run em this way.

[BARRY]

DO NOT DO IT REALLY BAD

[camarojoe]

I've always heard it was bad too, but my dad has a street rod with 31.50-15 bias ply Mickey Thompson Sportsman Pros on the rear, and he replaced the fronts recently with common radials (they were formerly Sportsman bias ply front runners) and noticed no difference in handling or drivability. Personally I wouldn't do it, and told him that too, but in his case, it doesn't seem to make any difference...maybe it's because the rears are already so much wider than the fronts anyhow?

Personally, I'd order up a pair of front bias tires too, it'll look cooler overall, and take any question out of the safety of it.

[Salvatore]

I agree with Joe. Why mix em? Buy some Pro Trac's for all 4 sides.

[StealthBird]

It's not good to mix, but if you're going in a straight line most of the time, and you're not prone to doing exit ramps at double the speed limit, there won't be a problem.

Before drag radials came along (back in 70's and 80's), almost all vintage Musclecars were shod with modern radials. It was common to bolt slicks on and go street racing for the night, or perhaps hit the dragstrip. It was rare that all 4 tires were changed over to bias, usually just the rears.

The reason you're not supposed to mix bias and radials is because the sidewalls flex at a much different rate between the two. If you have to do a emergency maneuver, the front (radials) will dig while the back (bias) will slide. So yes, it could be dangerous. But the tire manufacturers always make it sound like if you mix bias and radials, your car will explode.

Personally, I would change all 4 in order to get predictable handling, but you can run bias/radials at the track without any problem.

[BARN FIND]

I tend to think that leaving the radials on the front will make the the car safer not the other way around. Bite in two tires has got to be better than none at all. Plus he is going to be running grossly larger rear tires compared to the front so they may have some bite after all. And yes, I have done this before both on cars and trucks. (Think snow tires in PA in the 80's as just one example)

[njsteve]

It is common knowledge that you should never mix the two types.

Call me paranoid, but here it is from a lawyerly perspective: You know it's a no-no to do this based on the unpredictable handling characteristics...If you got into an accident with that car tonight, the insurance company would most likely deny your claim based on the fact that you contributed to the risk of an accident by installing the mixed tires...and the lawyer(s) of the person you had an accident with, or the innocent bystanders, etc, whether it was your fault or not, would have a field day bringing the mix and matched tires up in court. They'd make that the entire issue of the case, not the fact that somebody ran into you, but the fact that you put 2 radials and 2 bias plies on the car.

Remember the O.J. trial??? If the tires dont fit, you can't acquit.

I'd stick to all radials or all bias ply and avoid the risk altogether.

[TDW]

Thanks for the replies. I did a search on another site before asking here. The majority of the responses were it is OK to mix them. I have always thought it wasn't a good idea, so I was looking for real world experience. I will just order all 4 from Coker. Thanks again for your time.

[Keith Tedford]

Years ago I had a '79 Impala and I was running radials. Come winter I put on a set of bias ply snow tires. It was fine until I got on an old highway that was rutted from many years of too much traffic. The car would literally shoot from one side of the rut to the other. Scariest ride I ever had. With radial snows it was fine and the ruts weren't even noticeable. Perhaps different vehicles react differently.

[47Hammer]

Back in the late 70's I was running these bias ply tires that were actually recaps. They were called Caldwell Racing recaps and they worked better than the standard bias ply tire but they were hard to balance because of the weight.
After a few near misses (water across the road at speed) I started running the BF Goodrich T/A Radials on the front only and oh boy!! The rear end of that car would dance all around the corners until I matched the radials on all four corners. Much better and faster too.






Note the outer edges of the tread worn out.