The dangers of Used tyres

It is our opinion that used tyres are not worth the money you think you are saving. Firstly, consider that there is no manufacturers warranty on used tyres, so you have no recourse in the event of a failure. Secondly, your insurance company (both vehicle and possibly life insurance) will have issue with used tyres in the event of a claim.

In all instances ask yourself "why did the previous owner remove his tyres" before you consider this route. We are unaware of any country that requires tyre replacement at more than 1.6mm, regardless of what the salesman might tell you.

When purchasing a used tyre you have no idea how the tyre has been treated or maintained, or the conditions to which the tyre was subjected by the previous owner. When you look at a tyre, whether at the inner liner or the tread and sidewall, all you see are the outside layers of rubber. You cannot see what is between these layers of rubber, which is where your potential problems lie.

Each tyre has mutiple components making up the overall construction of the tyre. The terminology may change, depending on the type of tyre, but the components and their function remain principally the same. This diagram shows a few of the components that you need to know.


First, check the date code of the tyres. See our page on tyre age for further information. The last thing you want to do is purchase an overage tyre.

Second, are the used tyres designed for use in this country? Check their speed rating, load index (see our speed rating page for more information), certification, and application. Have they been homologated and tested by a reputable institution as all new tyres sold in this country are? Many tyres look the same, but they can in fact be for horse drawn cart or winter applications, which do not work out too well on our roads.

Should you be looking at buying used tyres, rather consider one of our moderately priced budget tyres that are sure to give you better service than any used tyre, for a fraction more than you are paying. If finance is an issue, we have a quick and easy online credit facility which you can take advantage of. We care for your life and would rather you make the right choice.

Key areas on a tyre that you must inspect, should you be considering fitting used tyres are;

THE TREAD

A simplified interpretation of the law on tyre usage states that you may only operate a tyre with no less than 1mm of tread remaining (anywhere on the tyres tread area) and no less than any tread wear indicator (which is usually set at 1.6mm).

Firstly, look to see if the tread is worn evenly across the entire tyre. Usually the shoulder area of the tread will be more worn than the crown (centre), possibly as a result of poor wheel alignment or under-inflation / overloading (which we address later). On occasion you may find that the crown of the tread has worn more rapidly than the rest, which is an indication of over-inflation.

Car tyres come with an original tread of approximately 8mm, depending on brand and type (SUV & 4x4 tyres can range from 8mm to 17mm).

If you only have 3mm of remaining tread at the lowest measured point on the tyre then you are only getting between 1.4mm and 2mm of usable tread. This means you are getting 20-28% of the original tyre to use. To calculate the remaining tread on a car tyre, divide the shallowest tread depth (in mm) by 6.6, which will give you an approximate percentage of usable tread in the tyre.

Note that once an irregular wear pattern is established on a tyre, it will continue to wear irregularly. You should feel the tyre by rubbing your hand along the circumference of the tread, in both directions, feeling for sharp leading edges on the tread blocks, which are an indicator that an irregular wear pattern is present.

When looking at a used tyre you may find small marks in the tread area that have been caused by penetrations. You may be told that these are superficial, but beware, they could penetrate deeper than you realise. Yes, the tyre may well inflate and hold pressure because the penetration has not reached through to the inner liner (which replaces the old style tube in a tubeless tyre), so all appears fine. The reality is that these penetrations can be down to the steel belts or casing plies and may have caused damage. A penetration to the steel plies can result in ingress of water and dirt particles, which in turn may cause rust on the steel plies or a separation between the plies and the rubber compounds to which they are bonded. Penetrations to the casing plies may cause breakage of the plies.

A tyre with any form of repair should be avoided.

Fine cracks in the tread grooves at the base of blocks are an indication of undue stress or weathering on the tyre, or possible misapplication. Thin patches of tread rubber flaking off may be a sign of a compound problem or possible misuse and could lead to delamination.

THE SIDEWALL

The first obvious signs to look for on a sidewall are surface crazing or cracking of the rubber, which would indicate; storage issues, overage tyres, prolonged exposure to the elements, compounding problems in manufacture.

Signs of bruising on the sidewall, where the rubber apprears to have been rubbed and is rough, are an indication of abuse. Sidewall blisters should also be avoided.

Pothole and kerb damage is not unique to South Africa, these events are commonplace worldwide and could have happened to your tyre without you being able to see it. Look and feel for soft spots or bulges and bubbles on the sidewall, indicating internal cords may be broken. Any form of bubble or bulge, circular or linear, on the sidewall is unnaceptable indicating that there is damage to the casing plies or delamination of the sidewall.

Sidewall cuts and nicks need to be carefully inspected . The casing plies are generally made from nylon or similar material and after being cut their tension is released and they withdraw partially into the sidewall rubber, making them difficult to see and leaving you with the assumption that there has been no damage to the plies. Cuts that penetrate through to the plies mean you are just buying an expensive rubber baloon.

Circumferential cracks on the sidewall, either near the bead, mid-sidewall or shoulder (near where the sidewall joins the tread) point to problems within the tyre.

Underinflation and overloading are commonplace. The effect of either can result in undue stresses being placed on the tyre casing, resulting in excessive heat buildup and will result in damage to the casing plies and degradation of the bonds between components.

THE BEAD

The bead is an area of potential concern as this is what keeps your tyre on the rim and helps retain the air. Any form of damage to the bead, no matter how small, can result in failure of the tyre. Repeated fitment and removal can often cause damage to the bead area. Discolouration of the bead area can also be an indication of high temperature, as a result of the tyre running under-inflated or overloaded.

INNER LINER

Any form of damage, creasing, roughness, discolouration, looseness, bubbles or damage within the area of the inner liner are a cause for concern as they could lead to spontaneouse tyre failure.