why you don't mix bias ply rear with radial front

[jarhead75]

In many forums, i have seen the question of wanting to mix bias ply rear slick with regular radial front tires.
Found this video on YouTube which is a great example of why not do this.

http://youtu.be/T8wIzXc_TTk

 

[NC85]

Could've been anything from watching the video. Rear psi too low, something on the track surface, mechanical failure.............

 

[GT500RedStripe]

Was more than the tires.

 

[jarhead75]

I agree, could have been much more than just tire choice but I have seen it time and time again. You get real bad wiggles on the big end from mixing the 2.
I've seen people pull out of the wiggle after letting off the gas. This guy seemed to keep it pegged until it was to late

 

[byeofcr]

All i could think of when it snapped hard right toward the wall was days of thunder line "this is gunna hurt"

 

[72SBC]

I've never had a problem, and I've been pretty fast. I really only notice the wobble when the psi is set around 10-12lbs, great for hooking but, you're dancing on the big end. That's with mixing and without.

 

[badblacklx]

A radial becomes dangerous in the front when it is a wide low profile tire. Similar to just bolting 15" slicks on back and leaving 18" street wheels in front. The reason a radial 15" in front is ok is because of small contact patch and the sidewall can give a lot easier to soak up some of the sidewall movement from the rear.

 

[scott_0]

eh, just because the dumbass hit the wall, does not automatically mean its from running bias plys with radials, thats just a silly assumption, as said, it could have been he was running way to little psi, or any number of other variables. and is it just me, or were those slicks huge on the little car?

 

[lilsilverponey]

I think the main reason you don't mix bias ply with a front radial is because bias ply tires are known for correcting themselves when you start to wiggle or lose control at the track. For instance, last time I took my car to the track I hit a water spot right when I hit 3rd gear (90mph) and went sideways toward the wall. The rear tires bit down when I got sideways and actually straightened the front of the car out. If I didn't have skinny tires up front and had a radial it would have held the grip and the car would have shot into the wall. I know a guy that totaled his TA recently because he was running a bias ply tire with a street tire up front.

 

[95gts5oh]

I think the main reason you don't mix bias ply with a front radial is because bias ply tires are known for correcting themselves when you start to wiggle or lose control at the track. For instance, last time I took my car to the track I hit a water spot right when I hit 3rd gear (90mph) and went sideways toward the wall. The rear tires bit down when I got sideways and actually straightened the front of the car out. If I didn't have skinny tires up front and had a radial it would have held the grip and the car would have shot into the wall. I know a guy that totaled his TA recently because he was running a bias ply tire with a street tire up front.

I've had some pretty scary swaying a few times when I left off at the end and each time it was when I had my normal street tires up front.

Although this guy seemed to be under power still so I suppose my case doesn't apply.

 

[98 N/A 4V]

Been running radials and slicks for over a decade now.

-Mark

 

[mr2cam]

I have been 10.65@124 with radials up front and bias plys out back, car would go strait down the track every time, running 8.5lbs of air pressure out back.

 

[Fat-cat]

never had a problem other then a slight wobble at 11psi rear tires. 146 mph pass. On both 17 inch and 15 inch radial fronts soft and stiff sidewall rears. thats just me though.

 

[rdsnk46]

Driver mod required.......

 

[Blk91stang]

No problem with radial fronts and bias rears either over hundreds of passes at 11.0

 

[STAMPEDE3]

You don't mix because they correct different and feel different when doing so.
Small corrections with radial fronts have a larger difference on bias rears than they would on radial rears.

Sure,many have made hundreds of passes without issue. I'm not gonna preach but it really isn't the right thing to do.
If you ever get into a situation you may understand then.

 

[jarhead75]

And this is what i love, we got some great replies about the topic for future guys with this question. I would say it all comes down to experience as well. Those of you with 100's of passes with this set up, you know your car and have mastered this set up. Now take a guy who hasn't had many passes on any tire and throw him in with bias rear and radial front and watch him hit the wall.
I think it takes a lot of seat time to really get to know your car. So why gamble on mixing tires if your not a seasoned racer.

Thanks to all of you for awesome answers.

 

[Tezz500]

Nothing wrong with alil wiggle.

Tires are fine OP. L2D.

 

[Tezz500]

You don't mix because they correct different and feel different when doing so.
Small corrections with radial fronts have a larger difference on bias rears than they would on radial rears.

Sure,many have made hundreds of passes without issue. I'm not gonna preach but it really isn't the right thing to do.
If you ever get into a situation you may understand then.

On point.

Topic should read: Radial front, Bias Ply rear not for Novice Drivers.

 

[psucobra]

ba-ba-ba-ba-b ba wiggle wiggle wiggle!!!