Take care of tyres
Bridgestone think before you drive campaign
Bridgestone think before you drive campaign
SOWETAN'S ROAD Rave and its sister publication Sunday World's World on Wheels motoring supplements are big on safety - hence our regular feedback to readers on all aspects of safe driving, adapting one's own driving style and the importance of attending advanced training and safety courses.
It's also part of the reason that we teamed up with leading tyre manufacturer Bridgestone to educate readers and motorists alike via the Think before you Drive campaign.
The campaign is drawn into even sharper focus this week as thousands of families around the country start preparing to head back home from public school holidays.
Families travelling by bus or car will hopefully be part of a preparation routine that includes refuelling and a check of tyre pressures on the vehicle.
As we revealed in our last edition of the Think Before You Drive Campaign story, tyres are probably the most ignored yet most essential safety item on your car.
Forget engine failures, blown gaskets and faulty electronics, the bottom line is that even with all these working, it's still up to the tyres to get the whole package going safely.
While many accidents and traffic incidents are blamed - directly and indirectly - on tyres, a number of key facts are ignored.
Like any safety mechanism or system, tyres are built for a specific purpose and need to be used in the correct application to ensure that maximum performance and benefit is achieved.
Use a tyre incorrectly or fit it onto a vehicle it's not meant for and there are bound to be problems.
If tyres are abused through bad driving, overloading of vehicles, or simple negligence when they are allowed to wear excessively, the potential for an accident is high.
It all comes down to our knowledge and understanding of tyres as motorists and road users.
As motorists, we need to make it our business to know everything there is to know about the tyres on our cars, from what brands they are to the way they are constructed.
HOW A TYRE IS MADE
A basic tyre is made up of different components, each playing a specific role.
Each tyre has a bead unit or bead ring on either side that is held in position by the air inside the actual tyre.
The bead ring is made up of either copper or bronze high tensile steel wire that has been platted to form a stiffened and high-strength anchor point.
Because of its high rigidity the bead ring anchors the tyre to the edge of the rim, forming a seal that prevents release of air.
The bead ring is a critical element that keeps the tyre rooted to the rim even during exertion of major lateral forces, for example during high speed corners.
The construction of a tyre is incredibly complex with each element playing a unique role and the actual bead unit is no different, itself a combination of different puzzle pieces such as rubberised covers and spaces, and something called bead fillers which are positioned above the platted bundle of wires that make up the ring.
It's one thing for the bead ring to anchor the tyre to the rim, but to maintain this rigidity and strength it requires the bead fillers which strengthen the lower sidewall area of the tyre.
The design and type of bead filler differs from tyre to tyre, so high performance tyres will have a unique bead filler construction when compared to commercial vehicle tyres.
As technical as it sounds, the simple reality is that the tyre would not stay on the rim if it was not reinforced and kept rigid with the various bead elements.
This is why correct tyre pressures are so important because any under-inflation coupled with overloading on a vehicle can put strain on that particular part of the tyre, causing it to flex.
This undue pressure starts to break up components of the tyre, ultimately leading to a potential failure and the dangers that go with it.
It's important to understand that in full motion, there are many forces transmitted via the tyre on to the road. With this transfer of forces and heat generated from the brakes, comes the potential for friction between the bead ring and the edge of the rim where the tyre sits, also known as the flange. This section of the tyre becomes a hotbed of force and activity and cannot afford to experience failure of the bead ring.
A significant precaution in this area of the tyre construction is something known as a chafer strip which surrounds the bead area where the most consistent and severe contact occurs.
This chafer strip acts as a buffer between the wheel and the tyre and stops the rim from chafing or rubbing harshly against the bead.
Apart from absorbing the forces and friction, it also acts as a protective strip during fitting and stripping of tyres.
KEEPING AN EYE ON THE CHAFER STRIP
Although the chafer strip is hidden from view by the edge of the rim, it needs a keen knowledge, understanding and eye to spot damage of the strip.
Much of the damage can actually occur before the tyres even touch the open road, with the fitment process needing to be scrutinised.
While a reputable fitment centre ought to not incur such damage, accidents will happen. So keep your eyes on the fitment process and if the tyre appears to hang or stick ask for it to be removed and checked for damage.
Talking of reputable fitment centres, there are a number of entrepreneurial roadside fitment operators who do not have the necessary technical expertise and training, so beware and visit them at your discretion.
Another way in which the chafer strip can be damaged is through excessive movement between the rim flange or edge and the bead.
This excessive movement is caused either by under-inflated tyres or through vehicle overloading where the tyre pressures are not adjusted accordingly to carry the extra weight.
Do a cursory inspection of the rim edge on either side of the wheel and if you find a residue of rubber or rubber flakes and particles at the contact area, it is likely there has been some damage.
Get the tyre checked out by a professional and insist that the tyre be removed from the wheel for inspection and technical assessment.
In the next article in the series we'll focus on the protective instincts of a tyre's inner liner and sidewall.