If we are to appreciate the tremendous advantages in tire repair technology, we have to start with a small factory making farm machinery and rubber products in Clermont-Ferrand, France, about 100 years ago operated by Andre and Edouard Michelin. The brothers became involved with tires in 1889 when an English cyclist called at their factory to have a punctured tire repaired. The repair took hours and drying took all night.
The Michelins were convinced there should be a better way to repair a tire and after several months of research they came up with a tire that could be repaired or changed in 15 minutes.
The tire-wheel assembly, which used 17 bolts, was patented in 1891 and an important industry was born. A punctured tire no longer was a catastrophe, but a simple incident.
There was much skepticism about a detachable pneumatic tire and something had to be done to promote and prove its ability to go long distances quickly.
Since road racing was very popular as a forum for stressing the reliability of manufacturers' products, the Michelin brothers turned to devising ways of using their pneumatic tires on cars.
The breakthrough came in 1895 when Michelin entered three cars in the 1,200-mile Paris-Bordeaux-Paris automobile race, the first ever run on air-filled tires. Only one Michelin entry, L'Eclair, finished. It was ninth out of the nine cars that completed the race.
This historic race is well-documented because of its significance in proving to the world that a car could run on pneumatic tires.
It would be another year before Goodyear was founded and three more before Firestone entered the tire business in 1899.
The Michelins took 22 tubes with them and in fact had more than 50 deflations. Many of them were caused by structural failures of the tire casing, others by penetrations from sharp objects.
Today, air loss due to structural failure has virtually been elimi-nated and nearly all punctures are due to penetrations by sharp nail-like objects.
Oddly enough, there seems to have been comparatively little development in tire repairing between the first days of the pneumatic tire and the 1920s.
``Blow-outs'' and punctures were quite common during that period and accepted as a small price to pay for mobility and comfort of the pneumatic tire compared with the solid tire or steel rim.
Permanent repairs could only be made by a hot vulcanizing process which was time consuming and expensive.
Temporary repairs could be made by fastening a fresh piece of rubber to an inner tube by means of an adhesive solution and by fitting a ``skived boot'' to the tire. Neither of these repairs were satisfactory in any way and the only effective way of overcoming tire failure up until the 1920s was to get a replacement tire or tube.
An American company developed a ``hot patch'' early in the 1920s. The patch was vulcanized by igniting a built-in fuel pan. A tube repair could now be completed in 10 minutes.
A further development followed when the hot patch incorporated afuel pan which could be ignited by a cigarette, and that company named their patches Camel, Lucky Strike and Chesterfield after cigarettes of that time.
A story I like most about the origins of tire repair material was the subject of an article, entitled ``A strange business partner,'' in the Saturday Evening Post. The firm which claimed to be the largest in the world at that time was Monkey Grip. Unfortunately, space will not allow the details which will be discussed in an upcoming article.
Throughout the 1920s and 1930s, tire and tube repairs were made by the original hot-vulcanization patch, the self-vulcanizing patch and the hot patch with the built-in pan ignited with a flame. Although the original sticky patch was still being used, it was gradually diminishing in popularity.
The next major development came when a European company (Stahlgruber) introduced a chemical-vulcanizing patch with a built-in face gum which relied on chemical activators in the cement to create a chemically vulcanized bond between the patch and the tube or tire needing no outside source of heat.
Since that time, further developments have taken place and the self-vulcanizing patch can be said to have reached the ultimate in terms of ease of application and efficiency in operation.
With the introduction of thetubeless tire in the late 1950s attention changed from the repair of tubes to the repair of tubeless tires and a veritable deluge of different repair methods quickly found their way onto the market.
Tire manufacturers themselves often recommended the use of astraight rubber plug pushed into the tire from the outside using a needle. The method fell into some disrepute because the plugs had a tendency to be ejected from the tire in service.
To offset the problem, some manufacturers added mushroom heads and others added ribs around the stem. Then came the tool that literally fired plugs into the tire. The problem here is that plugs fill the hole and do not always seal the innerliner.
One of the more revolutionary ideas at about the same time was the introduction of a type of tubeless repair that had no rubber content whatsoever! In its simplest form, it was just string dipped in tar and in its most sophisticated form it became a combination of a woven nylon sleeve with a plastic core and cover.
By the 1960s there had never been a greater profusion of different types of tire repair materials being offered around the world. It was an interesting period as manufacturers often had a combination of different methods of tire repair all of which were backed up by ingenious and sometimes conflicting claims as to their technical merits, methods of application etc. Unfortunately, there has been very little standardization of repair methods by manufacturers in the interests of the consumer.
Great Britain took the lead in the 1970s when it issued the British Standard on Tire Repairs (since updated). For the first time, suitable methods of tire and tube repairs were defined.
First, it laid down minimum requirements as to the size and construction of patches used for specific injuries.
Second, it gave equal approval to hot vulcanization on the one hand and chemical vulcanization on the other. It described all acceptable methods of repair, thus excluding any other method of repair not covered in the standard.
It excluded all repairs made from outside the tire. This was not because of any inherent deficiency, but unless the tire was removed from the wheel, the repairer couldn't be certain there was no internal damage.
Tire repair deserves to be respected and treated as a specialized business rather than a ``hole-in-the-wall'' activity practiced by poorly trained workers.