Hot Rods Running bias and radials?

I noticed that the car that is on the cover of the new Rodders Journal is running bias tires on the front and radials on the rear. I always thought that was a no no???Anyone else doing that? Does it affect handling?

 

I've had varying results with mixing them...usually it ends up getting your attention, when you least expect it.

 

I've always been told the same thing. Don't do it.

 

The tires guys used to say that radials are good followers but poor leaders. Way back when radials first became popular it was a common practice to run radials on the rear and bias plys on the front. I guess it had to do with cost or tire ware or something.

I would avoid it if possible but I would not be afraid to run one that way if that was my only option. Jim is right though it can get you into trouble easy enough, especially if your radio manages to separate plys which they are known to do.

 

Trailer queen?

 

Not a great idea. Simply put, they don't "respond" in the same manner. I haven't seen the article / car in question yet but, as everyone knows all too well, certain aspects of show cars are done for looks and not performance (let alone safety). Gary

 

Good example of bad practice

 

Actually the way that the car in question is described it is backward to the way that the rodders used to run them. Show cars especially got baby radials in the front and whatever wide tires could be found in the rear.

 

I use radials not traditional I know but don't mix um up.

 

My Chevy has big radials on the back and little bias plys on the front, oh, and manual steering. Two hands on the wheel while on Route 1 north of Boston - otherwise it has been fine for 6 years

 

The bias to radial switchover was just about finished when I started needing tires, so my info may be totally wrong. But I thought it was ok to run bias in front and radial in back, but not the other way around. The logic behind this is you didn't want your better braking tires (radial) in front because they would grab better allowing the rears to slide on past them causing a fishtail. With radial in back, they would grab 1st, and no fishtail could happen. Take this info with a huge grain of salt.

 

Maybe just a photo op.

 

From back in my Standard Oil gas station days when the Amoco Radial SS-120 radials came out. You could mix and match only if you installed the radials on the rear. Sidewall flexing was the issue. One of the big issues back then (1969-70) was when people would buy a set of those from us and during the winter pull out the snow tires (bias) and put them on. Then the fun started with the back end waddle.
Personally I ran a pair of those Amoco tires on my 54 Chevy back then, J70X15's were the widest I could get at the time. I ran F or G 78 14's on the front (bias ply) at the same time.
At the gas station I worked at we used to get a lot of "adjusted" branded tires. We would buy them for about .25 on the dollar from our distributor. Rarely we would get one that would not balance out. All that was assumed was that people were mixing tires and getting sway problems as a result.


Anyway, I would not install the radials on the front and bias on the rear on my own car.

 

From personal experience with my 48 mixing and matching radials and bias tires makes for an ill driving rig. That was back when it had a Camaro subframe in the front and coil spring setup in the rear.
I haven't got that issue in the mail yet so I'll have to reserve comment on the car in question until my issue shows up. My guess is that either it's a trailer queen or the driver (s) are so busy grinning and driving that they don't know if it drives perfect or not.

 

If mixing tire types, the bias should go on the front and radials on the rear. For equal sizes, radial tires are capable of developing far greater cornering force than bias. If you put the radials on the rear, they will use this greater cornering force to prevent oversteer if you drive into a curve too hard. With radials on the front, its very possible for the front to hold during a turn and the rear bias tires to get loose.

When the rear tires are substantially bigger than the fronts, it wouldn't make much difference which end was radial or bias since the bigger rears would develop more cornering force than the smaller fronts regardless of which end had the radials.

 

Bias tires don't develop more braking force than radials for equal sizes. The opposite is true. The main advantage of radial construction is the ability of the tread to stay flat on the road surface due to the stiffness of the carcass under the tread.

Its a common misconception that locking up the fronts will cause a spin. Once again, the opposite is true. Once the rears lock, the tires really don't care which way they slide. Sideways is just as easy as straight ahead. People tend to rationalize the action of locked rear braking as if it was a force pulling on the trailing end of a chain, but that's not the way it works in the real world.

When I worked for a tire manufacturer, we had some vehicles set up for basic braking tests that allowed us to turn the braking on or off to any individual wheel. The test consisted of running across a wet polished concrete surface at 60mph. A magnetic pickup would lock whatever wheels were selected, and the car would slide about 200 ft while the entering and exiting speed were measured and recorded.

With just a little practice it was easy to keep the car straight with the fronts locked. It was a little tougher to keep it straight with diagonal wheels locked, but not too bad. I never saw anyone, myself included, who could keep it straight with the rears locked. Within the first 50 ft after lockup, the rear would be out far enough that you'd have to either abort the test or go on down the track spinning like a top.

 

I bought a set of Coker classic radials for my '51 Ford to replace the Firestone bias tires. I took them to my shop to mount them. I got the fronts mounted and saw it was dinner time. I figured "I can finish this tomorrow", so I drove the 3 miles home. It was very obvious that there was a serious degradation in handling; it was almost like I was on glare ice. I mounted the rears the next day, and all was fine again. I don't know about radials in the back and bias in the front, but I strongly recommend against the other way.

 

I certainly wouldn't recommend it, but as a broke teenager in the 80's I drove my 55 BelAir with radials (new blems) on the rear and old used bias on the front. IIRC, it seemed fine to me. Of course, I was just a stupid kid and wouldn't have known better anyway since it was lowered with blocks in the rear and cut coils in the front.

 

Bought an old chevy pu for parts and ended up driving it as a work truck. It was ok around town but on the freeway, especially when wet, it would change lanes when I hit a bump. I later noticed it had a bias belt tire on the right front and after changing it to a radial, it drove like a new truck with no adverse problems.