News You Can Use

September 23, 2013/Bias vs. radial tires

RTA NEWS YOU CAN USE
September 23, 2013

In a recent RTA memo (SEPTEMBER 20, 2013) we asked for help
on behalf of one of our members regarding Bias vs. radial tires.

Here are the two replies we received. Both are being printed anonymously. Both replies have been slightly edited (one for size) and do not necessarily reflect the views of the Retread Tire Association. If you wish to have more information about the authors of either or both of the replies, please let us know, either by telephone to 831-646-5269 or by email to info@retreadtire.org.

REPLY #1

Dear Harvey, I will try to answer these questions as best I can in an effort to assist the person making this inquiry. ??What I need is quantifiable data that I can use to project savings from a conversion from bias to radial tires. From Independent Truckers to the largest of fleets with the exception of some third world countries they all converted to Radial Tires many years ago. Why do you think they did that? If you are still using bias ply tires you are living in the past.

I need the data that shows that: I will try to help by offering these statements from personal experience.

• Radials can be capped 1 or 2 times more than bias tires. Each New tire manufacturer prints a new tire warranty and it includes information on Retreading (Capping). Some guarantee up to two caps and some give no information. Some have a Casing warranty that covers their casing up to a certain dollar amount if it won't cap because of a defect in the casing, I personally find that this almost never applies since once the original tread is worn down to the USA legal limit of 2/32nds that if the tire had a manufacturing defect that it certainly would have appeared before the original tread was gone. Normally if a tire won't cap it's because of too many punctures, cuts & bruises of various types. ?To answer your original question, Radial Tires will not cap 1 or 2 times more than a Bias Ply Tire and no new manufacturer will tell you they will. Most large trucking fleets cap their tires once and sell the casings, some cap twice and sell the casings.

•Occurrence of run flats is reduced by X%. Let me ask a question here. When driving a vehicle of any kind with any number of tires on it WHAT CARRIES THE LOAD? ?Answer, Air. In simple terms a tire is simply a chamber that contains, air and acts a pneumatic spring to cushion the load!! No air you will have 100% failure with any tire no matter what brand. You cannot reduce the number of flats with a Radial vs. a Bias ply tire, yes Radial tires do tend to deflect foreign objects to some degree but if you run over a foreign object and it penetrates the tire you will lose air and if not discovered and properly repaired you will have a run flat and a potentially unrepairable tire. So it does not matter if you are using Bias or Radial tires.

• Occurrence of punctures is reduced by X%. I have been in the tire business for over 40 years and I have never seen anything in print that discusses this from any manufacturer. I personally do not think that any manufacturer is willing to stick their neck out on this one. Why? If you hit an object in the road unless it deflects for some unknown reason it is going to penetrate the tire regardless of what type it is and you will have a flat tire. I think that Radial Tires in fact do offer better casing integrity and in fact many are repairable after being run low on air where Bias tires usually are not. However in any case if the tire is run low on air or has a complete air lose you will lose the tire and have a catastrophic failure

•Radials wear XX% longer that bias tires. This again is a tough question. Radial Tires simply because of their Casing design create less rolling resistance and therefore will increase tire life, Fuel Mileage and driver comfort (Less Fatigue). Tire wear pretty much depends on Tread rubber Compounding. Every Manufacturer uses different rubber compounds in different tread patterns to achieve maximum tire life. The recent EPA guidelines called Smartway are in my opinion the first big step in uniformity for the Truck Tire industry. It created testing procedures and standards that must be met to qualify for Smartway Certification. Any Tire Manufacturer selling tires in the USA market must be tested by an EPA approved testing lab and must meet the minimum requirements for certification. I suggest you study the Smartway guide and certification for tires. Just Google Smartway and it will take you to the site.

REPLY #2

Generally radials are better overall, but in some performance points even outstanding compared to bias tyres.

Major points being:

-far better puncture resistance in tread area, reducing significantly fleet downtime and expenses.

-runs much cooler, less separations and rolling resistance that leads to less downtime and fuel costs

Although you mentioned this is not important (can not imagine how can it not be…)

-no need of casing venting in retread process and humidity created separations only a memory.

-rim standardization helps the fleets

-easy retreading process eliminating use of rims (can be cured on double envelopes or ARC rings

(Trademark of Bandag)

-much better traction and wider footprint

-over the road applications offer a huge mileage difference

But as you said your business model calls for some different needs. On construction and off the road solutions biases still have some users where sidewall punctures are an issue.

We in Europe do not have any more Biases on the road solutions. I reckon different markets act differently because of new tyre supplies. Europe switched early to Michelin´s patented radial construction and as of high market share of Michelin everybody followed after it was possible for patent rights. US did not switch that early, I have also heard that after Michelin´s rights opened up, all bias mfg. machinery was just renewed by new tyre manufacturers and there was reluctance to invest again—who knows?

Also casing availability might be a criterion for you. Do you have good brand radial casings available on your market? We have seen in past years in Europe a huge demand for casings and prices are going up.

You might find following link interesting:

http://www.forconstructionpros.com/article/10307455/pros-and-cons-of-radial-vs-bias-ply?page=2

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Our thanks for the authors of both of the above replies for taking the time to share their views with the readers of this RTA NEWS YOU CAN USE memo

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THOUGHT FOR THE DAY

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