I recently received a letter from a commercial tire retreader who expressed a concern that many retreaders have:
I have spent the last three years going through the process of making all production of our precure retreads look better than anyone else's. My production staff has tolerated changes in buffing techniques, casing preparation, building methods, wicking methods, envelopes, and the task list goes on and on!
Our facility produces, on a continuous basis, the best looking, best performing retreads anywhere in our part of the world. However, so far in 1999 we have experienced more ``returns'' on tires with sidewall repairs than any other issue.
When any tire is returned we look into the reasons why. On these type returns I have each tire re-inspected internally and externally to make sure the placement and proper size patch material was used and to check that final inspection personnel were doing their job correctly.
I have the tire remounted on a wheel and inflated to 100 psi so we can see what the customer is seeing. Then we measure the bulge to insure it is well within the 3/8-inch industry standard—which they are—and then I follow up with a phone call to determine the reason for the return from the technician or customer.
The follow-up responses overwhelmingly point to one of two issues: fear that the Department of Transportation will sideline the vehicle or that the appearance of the tire looks less than safe.
Numerous conversations with repair suppliers, repair technicians, and our own in-house testing of various materials and methods conclude that we will not completely take away the bulge appearance issue when the tire is mounted and inflated.
As a person weaned on retreading and nowadays looking out for the bottom line, I have a hard time rejecting casings for repairs that can be properly and safely installed just because they don't look good!
I will be the first to admit that the sidewall bulges infringe on the otherwise new-tire look we have accomplished in our finished appearance methods here.
You spearheaded (The Maintenance Council's) Task Force that put the ``Blue Triangle'' identification in place for retreaders so that the DOT could identify the bulges as repairs. Have we become so competitive with the resurgence of mold-cure systems, matched-splice precure, Unicircle, Eclipse, Ring-tread etc. for the sake of appearance, that we prematurely scrap tires that otherwise can be safely used because of a sidewall bulge?
Vice president of operations
Sutton Tire Co.
Despite today's flourishing economy, most fleets still are only making a few cents for every dollar they spend to haul freight. The economics in the trucking industry are not yet to the point that fleets can sacrifice cost-efficient tire performance for appearance. So don't stop repairing yet!
I think the root of this problem is ignorance and a lack of understanding on the fleet's part. We—the trucking and tire industries—have been working on this problem since the early 1980s.
In 1983, the Commercial Vehicle Safety Alliance (CVSA), the national organization of state inspectors, accepted the use of the Blue Triangle as an indicator of an acceptable, repair-associated bulge, provided the bulge was under 3/8-inch.
The Maintenance Council (TMC) issued Recommended Practice RP226A Radial Tire Repair Identifier (Blue Triangle) to advise fleets to use this identifier to avoid problems with inspectors and still maximize their tire life.
It is not unusual for section repairs in radial tires to bulge when the tires are inflated. The contour change is caused by the slight stretch of the rubber in the repaired area when the tire is inflated since there is no steel supporting this area any longer. The bulge is usually as wide as the repaired area and normally extends down towards the bead. Sometimes it may appear on both sidewalls.
All repair material manufacturers have designed their radial truck tire repair units to adequately and safely reinforce the repaired area provided the repair is made properly. They all expect some section repairs to bulge due to the tire's internal pressure.
One or two repair manufacturers have played around with steel reinforced repair units to prevent the bulge, but the difficulty in installing these extremely stiff patches that must be aligned perfectly perpendicular to the bead is incredible and not practical in a real-world environment.
So the repair-related tire bulge is here to stay. From a vehicle inspection standpoint, a bulge less than 3/8-inch is not a problem as long as the blue identifier is used. Inspectors in all states recognize this symbol.
From a safety standpoint, as long as the repair is made properly, a tire with this type of repair-related bulge will run up to thousands of more miles. You can recognize an improperly made repair and its associated bulge externally by the size of the bulge and the cracks or breaks in the repair rubber that usually are evident.
An internal inspection will confirm the problem. The cause is usually the use of too small a repair unit or not removing all the injury when making the repair.
Many fleets claim to have problems with drivers who object to these bulges or are afraid that they will cause enroute delays. I think this last issue is the real problem. If drivers were the only concern, these fleets could install tires so that the bulges faced to the inside, or put them on inside dual positions. However, the specter of expensive emergency road calls is probably what is scaring them.
Enroute delays represent a major cost factor for most fleet operators today. Fleets pay an average of $300 for a road call, $130 for driver delay time, a delay penalty if they are hauling just-in-time freight, in addition to the cost of a replacement tire and the possibility of losing a customer.
So they understandably may be a little gun-shy of a tire condition that looks ominous. Nevertheless, fleet operators should intelligently weigh the benefits of section repairing tires against the possibility of an enroute delay.
I would suggest you put together a packet of materials to present to the fleet since an education effort is really needed. Include a copy of the TMC's Recommended Practice 226A, a letter from your repair materials supplier stating that repair-related bulges under 3/8-inch are acceptable and can be expected even when repairs are made properly.
Provide the fleet operator with a bulge gauge that can be sourced from the International Tire and Rubber Association or your repair or retread rubber/equipment supplier. Show them how to use it. Then compute the number and cost of the tires the fleet is throwing away annually because of its rejection of repair-related bulges or its refusal to section repair tires.
This number should be eye-opening and at least persuade the fleet operator to give the company's current rejection policy some reconsideration.
If this fails, offer to take these tires off the fleet's hands and resell them to a trucker who needs reliable retreaded and repaired tires. Make it obvious that other fleets have long accepted the tire repair-related bulge as a non-issue.
Don't forget that beauty is in the eye of the beholder. While retreaded tires are getting more gorgeous every day, low tire cost per mile will still turn on fleet managers.