Tire myths have their limits

When you visit tire shops around the country, you find owners and their employees want the opinion of the guy from the tire company about tire myths, so whenever a customer shows up they will have the right answer. Here are three classic cases where one will need the right expertise, and in some cases a bit of diplomacy, to face situations where a customer needs the truth.

1 — Another break in the wall

The first is the classic sidewall tear or break. The picture shows a clear separation from the bead almost to the tread. It will show as a bubble in other cases. This time, it is a case where the bead is broken and the sidewall torn. Claiming product default is out of the question here. In fact, the answer would become obvious if you visited a tire plant. It is absolutely impossible to have a rupture in the steel bead because it is woven in spiral and not welded. If there was a defect, it would not inflate when new.

Causes of this situation are improper mounting or dismounting by the technician. Too little or no use of tire lubricant, wrong positioning on the rim or overpressure after mounting can lead to such fracture. Too often, the recommended beading air pressure is exceeded because not enough lubricant is used. In these cases, warranty is always voided.

As far as a bubble on the sidewall, it is generally caused by an impact (pothole, curb, etc.) Again, it is not a product defect.

2 — Puncture repair from shoulder to shoulder

In the this picture, we find a nail in the shoulder of a tire at the precise flex point between the sidewall and the tread. It is the kind of puncture a repair shop cannot address. In fact, it strictly forbidden to repair a puncture that is located outside the width of the belts that compose the tread. Whatever puncture repair method is used, it must be in the central part — in between the arrows in the drawing above. The steel belts area is stiff enough and the repair will hold. Tire manufacturers forbid any repair outside the belt width for any passenger or light truck tire. Bad news for your customer, maybe; but safety must be your first concern.

3 — UHPT: Winter tires with a lesser speed rating. Why compromise?

Most tire shop owners and retailers will agree that often a speed index is lowered when offering a winter tire. The idea is to make the sale easier and more affordable for your customer. Very nice on your part, but is it in fact the best solution?

I had the opportunity to visit many tire manufacturing plants over the last 25 years and the tire engineers are unanimous: an Ultra High Performance Tire is designed to work in harmony with a vehicle — weight, power, driving gear — and its suspension components. The sidewall rigidity and the tread pattern — unidirectional, asymmetrical — must comply with the type of suspension and the engine package to provide the best possible ride. So, in short, a spec tire and its properties that is mounted as OE equipment on a vehicle is chosen to blend with the chassis, engine power, brake system and suspension components..

Installing a winter product considered high performance — speed rating V or more — on a vehicle that is homologated with a lower speed rating — T for instance — and a softer suspension is not recommended. The tire compound will not work to its limits, suspension components will be continuously stressed; and both will wear faster because the contact patch will not be optimal.

On the other hand, mounting a softer tire (T), with a more flexible sidewall linked to a stiffer suspension, is no better solution. This time, the tire compound will be stretched to its limits while the suspension will no longer work to its fullest: consequently, the ride comfort and road worthiness will deteriorate and the wear will be felt mostly on the tire shoulders.

So, starting next Fall, it would be useful to recommend exactly the same size and the same speed rating as the OE when offering a winter product. Your customer invested a few more bucks in a vehicle bound to provide a better ride. Why would he compromise the ride designed by the manufacturers’ engineers for a few dollars in tires?