Motorcycle tyre damage can occur in a variety of ways. Most of the time this damage can be inspected from the outside but occasionally a tyre can be damaged internally and this isn’t possible to inspect without removing the tyre.
The main areas to inspect are:
Surface cracks, flat spots or bulges
A tyre that has been stood for a length of time can become damaged to the point where it is not safe to use. If a tyre stands on a freezing cold surface (like a concrete garage floor) the sub-zero temperatures will likely flat-spot the tyre or crack the tyre, rendering it unusable.
Likewise a tyre that’s been out in the sun, wind and rain will prematurely age and even if it’s only a couple of years old, it could become cracked or leached which would make it unsafe for use.
Occasionally a tyre can start to delaminate if it is subjected to harsh weather conditions and this will manifest itself as a small blister on the tyre’s surface, usually around the size of a two-pence piece.
Sidewall damage
Any damage to a tyre’s sidewall is serious and will likely render the tyre unusable. Any deep scratches, lacerations or any thread poking through the sidewall means the tyre is not safe. If you’ve hit a kerb (either through crashing or just riding up one) you may have damaged the sidewall and your rim may even have pinched a small nick in the tyre’s sidewall.
Some tyre foams will also mess around with a tyre’s composition, so if there’s foam that’s been sat in your tyre for years, it might have weakened the bead or sidewall.
Delamination
This is rare but occasionally a tyre fails, through no fault of the rider. This is usually when the outer tread separates from the tyre carcass. This is a serious issue as strips of the tyre will shear off, potentially damaging your bike or you the rider. In the worst case scenario parts of the tyre will get bound up in the drive chain or axle or the tyre will rapidly lose pressure.
Delamination can also be caused when a tyre is incorrectly inflated and worked hard, i.e. a prolonged high-speed run with an under-inflated or over inflated tyre may cause the tyre to fail. You can check for any signs of delamination by looking for blisters on the same point of the tread at various points around its circumference.
Bead issues
The tyre bead helps seal the tyre to the rim. Modern motorcycle tyre changing machines are very good at getting the bead onto the rim without over-stressing it. However if a tyre has been fitted by hand or removed and fitted to a rim multiple times, it can weaken the bead. Check for any tears or signs of wear where the tyre meets the edge of the rim.
There were, a few years back, some Pirellis, for example the original Rosso Corsa, that were built with a very soft bead and this caused issues when fitting. What would happen was that when you used a tyre lever to get the tyre onto the rim, you’d inadvertently nick a tiny tear in the bead. The customer would come back two days later with a flat tyre and you wouldn’t be able to find anything. It was only when taking the tyre off the rim and inspecting it closely that we’d see this tiny nick in the bead, which caused the tyre to lose pressure. One to look out for if you are scratching your head trying to diagnose a puncture.
Tyre age
All motorcycle tyres will have a date stamp on the sidewall. If your tyres are more than 10 years old, you need to fit a new set. If they are between 5 and 10 years old, they are definitely past their best and we’d advise replacing them. As tyres get older they start to perish and often this is most easily seen where the tyre tread groove meets the tyre surface; any small cracks will show you that the tyre is leaching its oils and therefore it won’t have the properties its designed to have to perform properly.
Here at Two Tyres, we advise customers not to fit tyres that are over 5 years old as you really don’t know their true condition and we see far more of these come back with age-related failures than any other new tyre.
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