Mon | Aug 21, 2017

Garth Rattray | Reduce risk of tyre failure

Published:Monday | June 6, 2016 | 6:00 AM
Use the lug tool to crack each lug nut on the wheel. This process will need some amount of force to loosen each nut and body weight should be used if necessary.

I used to own a Toyota Hiace Grand Cabin (family) minibus. I had just got home from the airport with my relatives, offloaded everyone and their luggage, when the right front tyre exploded while the empty vehicle stood parked in the driveway. I shuddered to think what would have happened if it had exploded a few minutes earlier - it could have cost many lives. The tyre experts examined the carcass and deduced that a vulcanised patch somehow compromised the integrity of the sidewall.

Two weeks later, the left front tyre went flat from a nail puncture. The repairman couldn't patch it because he observed that the section that hugs the rim (where the bead is) was cracking and shredding. That tyre was also about to blow out!

Concerned, I took the vehicle to the agent/distributor that imports that particular (well-established, tried and trusted) brand of tyre. As soon as they examined them, they realised that the tyres were too wide for the rims. I explained that the tyres were recently purchased from one of their 'reputable' dealers and that (like everyone else) I depended totally on their expertise for guidance. I expected them to know the appropriate tyre for the type of vehicle and rim and not simply squeeze on any tyre that would fit.

The distributor repeatedly assured me that they educated and warned their agents, but added that several of them sell tyres just to 'make a money'. Some will sell tyres to get rid of old stock or to satisfy their customers' aesthetic desires or whims without regard for safety (proper specifications, proper fit). In some instances, regular tyres are fitted on to hard-working, heavily laden commercial vehicles to cut costs.

 

MOST IMPORTANT

 

Tyres generally consist of more than 100 separate components, including natural and synthetic rubber, steel, nylon, silica, polyester and petroleum. They are the most important part of any vehicle, yet they only have a contact patch ('footprint') about the size of the average man's sole. That's all that keeps us on the road. Tyre failure accounts for 57.1 per cent of our highway fatalities. Since more and more highways are being constructed, this will translate into a serious problem in the future.

Tread separation and/or blowouts might take place because of manufacturing flaws. However, the most common cause of blowouts is underinflation, which causes flexing of the sidewalls, which generates extreme heat. Overloading will do the same thing. Underinflation with overloading (common in Jamaica) is a perfect recipe for disaster. Combine all that with excessive speed and ill-fitting, cheap tyres and catastrophes will occur.

Drivers should examine their tyres regularly for symmetrical or asymmetrical wear. Wheels should be properly balanced, aligned and rotated every 13,000km or so. Tyre pressure should be checked with an accurate air-pressure gauge monthly. Always insist on the same size tyres that the manufacturers put on the vehicle. Used (pre-owned) vehicles may be wearing inappropriate tyres, so always consult the handbook or driver's door jamb for tyre specifications and inflation pressures.

 

UNUSUAL ROAD NOISE

 

Just a few days ago, the daughter of a very close friend suffered a puncture of her right rear tyre while on an out-of-town trip. She stopped at a roadside tyre repair shop and they patched the hole. She became aware of an unusual road noise emanating from the same tyre just before it suddenly blew out. She was sent into a wild, scary spin which culminated with the car slamming into a metal pole.

The car was extensively damaged but, luckily, no one was hurt. When she examined the blown-out tyre, she realised that it didn't match the rest of them. The guys at the repair shop had switched her fairly new tyre for a worn one of a different brand. Their dishonesty destroyed her car and could have caused the loss of many lives.

Those frightening situations have taught me to be vigilant and read up on the appropriate type and size of tyres specified for the vehicle. And, from now on, I will have to watch closely whenever I have any flat tyre repaired. We can't trust anyone with our lives.

- Garth A. Rattray is a medical doctor with a family practice. Email feedback to columns@gleanerjm.com and garthrattray@gmail.com.