Tyre Care

  • Tread Depth Rules

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    1. The law states that there should be a minimum tread depth of 1.6mm. It must be measured across the central 3/4 of the tyre and all the way round it too.

    What does this mean in practice?

    This means that the depth of the grooves MUST BE NOT LESS THAN 1.6mm.

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    2. The second part of the law says that the 1.6mm measurement must be across the central 3/4 of the tyre.

    This means that at any point across the main part of the tyre, the tread depth MUST BE NOT LESS THAN 1.6mm. ..

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    We recommend that you use newer tyres for the rear set, for extra safety in unforeseen or difficult situations (emergency braking, tight bends etc) particularly on wet surfaces.

    Numerous tests have shown that it is easier to control the front wheels than those at the rear.

    Front tyres generally wear quicker than those fitted at the rear, particularly on front wheel drive cars, which are currently in the majority.

  • New Tyres To The Rear

    We recommend that you use newer tyres for the rear set, for extra safety in unforeseen or difficult situations (emergency braking, tight bends etc) particularly on wet surfaces.

    Numerous tests have shown that it is easier to control the front wheels than those at the rear.

    Front tyres generally wear quicker than those fitted at the rear, particularly on front wheel drive cars, which are currently in the majority.

    New tyres fitted in front

    • The behavior of the car will change, because the front / rear balance will be reversed
    • The driver, used to a car with less grip at the front, will therefore be taken unawares
    • On a slippery road, the rear will lose traction before the front of the vehicle
    • The driver will have no chance of controlling the rear, and will be tempted to accelerate further, which will amplify the spin effect. Only an experienced driver will be able to recover from this dangerous situation…

    New tyres fitted at the back

    • The handling of the vehicle will be similar to that known by the driver before the tyre change, because the traction balance will be the same
    • Rear traction will be better, and the driver will be able to control and steer their vehicle without a problem by decelerating and turning the steering wheel in the direction of the bend

    We advise you to reduce the risks you take by fitting new or less worn tyres at the rear of the vehicle for better grip on bends and extra safety.

  • How To Read A Tyre

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    Ever wondered what the markings on the side of a tyre mean?  205/55 R 16 91V This is the size and characteristics of the tyre:

    • 205: This is the section width of the tyre. That means the overall width of the tyre in mm.
    • 55: This is the aspect ratio of the tyre. That is the sidewall height of the tyre as a percentage of the section width.
    • R: This mean the tyre is of Radial construction.
    • 16: This is the internal diameter of the tyre.
    • 91: This is the load index. How much weight the tyre can carry.
    • V: This is the speed index. The maximum speed the tyre is designed for.
  • Use Air To Save CO2

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    They must be checked when the tyre is cold (by cold we mean the ambient outside temperature where the tyre is to be used).

    Tyre pressures must be checked regularly, about once every two weeks.

    A drop in pressure can be caused by:

    • The natural leakage of air through the walls of a tyre
    • Drops in ambient temperature
    • Small perforations that, in a tubeless tyre, may not lead to immediate deflation but rather deflation over time, (a slow leak!) . This in turn can lead to irreversible damage due to the tyre running in an under inflated condition

    Why check your tyre pressures?

    • Maximise tyre life
    • Minimise tyre related fuel consumption
    • Minimise greenhouse gas emissions
    • Save money!
  • Tyre Section

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    1. The inner liner.

    A layer of airtight synthetic rubber.This is found inside the tyre and is the modern equivalent of the inner tube.

    2. The casing ply

    This casing is composed of fine textile fibre cords, laid down in straight lines and sandwiched in rubber. These cords are a key element in the structure of a tyre and enable it to resist pressure. In each individual ply of a car tyre, there are about 1400 cords, each one of which can resist a force of 15 kg.

    3. The lower bead area

    This is where the rubber tyre grips the metal rim and its role is to transmit the power from the engine and braking effort from the rim of the tyre through to the contact patch.

    4. The bead wires

    The bead wires help to hold the tyre onto the rim. They can each take a load of up to 1800 kg without the risk of breakage and you have eight of them on your car, two per tyre. Thats a massive 14,400Kgs of strength where an average car weighs about 1,500kgs. The bead ‘wire’ is actually a cable but is made from a single piece of wire woven in a circle with the ends securely joined together for maximum strength.

    5. Supple rubber sidewalls

    These help to protect the tyre from shocks that could damage the casing, eg minor shocks against pavements, potholes etc. There is hard, protection rubber where the tyre joins the rim.

    6. Bracing plies

    Reinforced with very fine, very resistant steel cords in a rubber sandwich. These two, (occasionally more), plies are stuck together and cross the tread area at angles of around 60∫ to each other. When the tyre is cured (baked), their steel cords cross the casing cords to form triangles. This is known as triangulation, and it makes the top of the tyre (its crown) rigid.

    The plies encircle the entire crown of the tyre, and perform a very complex role:

    They must be sufficiently rigid around the tyre’s circumference that they aren’t stretched by the rotation of the tyre so that the tyre doesn’t stretch and become larger.

    They must also be rigid across the tyre, to resist the stresses and strains of cornering.
    They must also be flexible enough, to “absorb” deformations caused by bumps and lumps in the road and other obstacles that may be found.

    To make this work, steel has to be bonded with rubber which is very difficult to do in they way that we need it to be done, (it is not just ‘glued’) but Michelin has mastered the art of perfect bonding between these dissimilar materials, and which is absolutely essential to your safety.

    7. Safety ply

    This cord allows the tyre to maintain a stable shape under the effect of speed and to reduce the effect of friction heating. It is reinforced with (generally) nylon based cords bedded in a layer of rubber and laid around the circumference of the tyre to prevent the effect of speed stretching the tyre. We sometimes refer to this as a ‘zero degree belt’.

    8. The tread layer

    The tread is laid over the bracing plies. It is the patterned part of the tyre that will be in contact with the road. The tread in the contact patch (the part of the tyre that touches the road) must be able to resist very significant stresses. The tread rubber compound must grip on all types of surfaces, resist wear and abrasion, and heat up as little as possible.
    All that then remains is to mould in the tread pattern and vulcanize (bake) all these semi-finished products together to form what we know as a whole tyre.