Like rust, the worst type of tyre damage is the type you can't see.
SmartCarSpecialist were working on a car and found tyre side wall damage. What makes this unusual is
the damage was only on the inside edges of the tyres. The visible outside edge of all the tyres were fine.
There was a little confusion as to what caused this damage but it's a problem I had already researched.
To save material, road management companies started using these instead of full length speed bumps.
These allowed motorbikes and lorries to travel unimpeded and are positioned to only slow down cars.
The problem is, the way they are positioned, they really don't slow your car down.
You can easily drive at full speed over these with almost no discomfort or bad noises from the car.
However, it's the fact that you don't slow down that causes the issue on the inside tyre side wall.
Here we have a fortwo driving on a flat road. Roads with speed bumps tend to be 30mph or 40mph.
See what happens to the inside of the tyre when the car hits and straddles a speed cusion.
The inside tyre wall deflects and the suspension doesn't move, however, the weight of the car keeps it flat and
level. All of the movement is in the sidewall which causes damage. It's almost like driving with a flat tyre.
The rear wheels can be affected in an even worse manner due to 2 added issues.
Not only is the weight of the engine over the rear wheels, the negative camber is
opposite to the camber of the speed bump so you get more side wall deflection.
Ideally, you should travel over these speed pillows with 1 wheel going over the top and 1 wheel going inbetween.
Unfortunately this is slightly less comfortable and causes you to slow down but just think of the cost of tyres.
A pot hole (a hole in the road) is pretty much the reverse of the speed cushion above.
Going into the hole isn't usually the problem, coming out of the pot hole causes the damage.
Goes without saying, avoid pot holes if you can, especially if you have...
If you have Brabus alloys, you should be extra careful as the low tyre profile doesn't offer much
protection so the deflection of the tyre can be transfered straight to the alloy wheel causing it to bend.
Excessive damage to the tread is usually easily spotted under your regular inspection.
However, this particular tyre went from nearly new to this illegal and dangerous racing slick in 4000 miles.
Replacing the tyre every few thousand miles is an option but it's better to stop it happening.
More often than not, if your wheel alignment (toe and and toe out) is out on a car, the steering wheel won't be straight when the car is driving straight or the car will shuffle at the front or squeal from the tyres.
However, in this rare case, both wheels were misaligned the same amount so counteracted each other.
With the incorrect toe in or toe out alignment, you tyre isn't rolling straight.
Essentially you are dragging your tyre sideways down the road which drastically increases wear.
Many garages have the ability to perform tracking realignment on your car.
If you find you have uneven wear or an off centre steering wheel, get it checked.