Damage to truck, bus and coach tyres may be caused by a variety of external factors.

For example, improper axle alignment or play in bearings can damage a tyre, as can driving with insufficient tyre pressure. The following chapter describes common damage to the tread area, the sidewall and the bead caused by external factors, and gives recommendations that will help you to prevent avoidable damage.

Abnormal one-sided wear

Cause
Abnormal one-sided tread wear arises as a result of tyre constrainment caused by wheels being inclined to the direction of motion. Scale-like or feather-edged wear is often seen at the shoulders. This wear pattern comes about by excessive toe-in/ toe-out values or crooked axles. It also occurs if corners are regularly taken at  excessive speeds.

Recommendation
Correct axle and wheel alignment

• High center of gravity of vehicle
• Unsteady loads
• One-sided load distribution
• Bent trailer tow-bar
• Play in the trailer coupling ring

Recommendation

When wear patterns of this sort occur, the vehicle should be  checked to see if any of these possible causes apply.

In order to stabilize the tyre cross-section, be sure to maintain maximum permitted tyre pressure

Cause
Wear patterns of this nature are caused by high lateral strain, for example by fast cornering and by underinflated tyres. A high center of gravity on the vehicle further increases this tendency toward pronounced wear.

Recommendation
Ensure sufficient tyre pressure to stabilize the tyre cross-section for the load condition.

Cause
Tyre pressure too high or high proportion of journeys without load or only with partial load.

Recommendation
Adjust the tyre pressure to the load situation.

Cause
Strain caused by slip is a result of high circumferential or lateral forces and is increased by excessive tyre pressure or insufficient wheel load.

Recommendation
Adjust the tyre pressure to the load situation.

Cause
Unfavorable combination of various vehicle vibrations in low wear use, e. g. on motorways. Only occurs on tyres on non-driven axles (front axle or trailer). Free-wheeling grooves have no influence on the structural durability of the tyre.

Recommendation
In the case of tractor tyres: continued use on driven axle.

Cause
Difference in diameter on dual tyres. Varying tyre pressure on dual tyres. The tyre running on lower pressure is subject to
excessive slip. Irregularities on the vehicle, e. g. too much play in bearings or joints or defective suspension.

Recommendation
Only fit dual tyres of approximately the same diameter. Keep both tyres in dual arrrangement inflated to specified pressure level. Remove any play in bearings and/or joints or repair the suspension (springs, shock absorbers).

Cause
Cuts caused for example by bent or protruding vehicle parts or by foreign objects trapped in the wheel house.

Recommendation
Regular inspection of the vehicle and its tyres for such causes.

Cause
Localized wear of the size of the ground contact patch, caused by:

• Excessively sharp braking (emergency stop)
• Brakes locking, for example as a result of incorrect adjustment of the trailer brakes or defective brakes

Recommendation

• Avoid unneccessary harsh braking.
• Check brakes and braking system and have adjusted where neccessary.
• Install automatic anti-lock brake system.

Cause
Too deep regrooving down to the belt. Damage of this nature, combined with the effect of dirt and moisture, causes the steel cords to rust. This may render the tyre unsuitable for remolding. In the final stages this can even lead to premature tyre failure.

Recommendation
Remove the tyre immediately and remold it if possible.

The tyre manufacturer’s instructions regarding regrooving should be followed under all circumstances. Exposed steel cords Tramline wear.

Cause
Spinning of the drive wheels on stony ground - can be exacerbated by moisture and overinflation.

Recommendation
Adjust the tyre pressure to the load situation. Use special tyres if necessary.

Cause
Effect of sharp-edged objects (stones, glass, metal, etc.)

Recommendation
If tyres with deep localized cuts can be repaired or remolded, this should be done by a tyre expert.

Cause
Break in the casing caused by sudden sharp deformation of the tyre, e.g. when driving over an angular object at high speed.

This is exacerbated by overinflation or overloading.

Recommendation

• If obstacles cannot be avoided, they should be passed slowly.
• Tyre pressure should be adjusted to the load situation.

Cause
Effect of sharp-edged objects (stones, glass, metal, etc.)

Recommendation
If tyres with deep localized cuts can be repaired or remolded, this should be done by a tyre expert.

Cause
Temporarily driving with insufficient tyre pressure or on a flat tyre, e. g. due to a nail puncture.

Recommendation

• Tyres which must be removed prematurely due to damage should be checked with particular care for further usability. Often it is very difficult or impossible to establish initial damaged to the casing, which may lead to premature tyre failure.
• If a tyre in a dual arrangement fails, stop the vehicle as soon as possible to prevent the second tyre from being dammaged as well.
• Adjust the tyre pressure to the load situation

Cause
Rupture in the casing caused by sudden, sharp deformation of the tyre following forceful impact by an obstacle or object.

This is accentuated by excessively high tyre pressure or overloading.

Recommendation

• If obstacles cannot be avoided, they should be passed slowly.
• Tyre pressure should be adjusted to the load situation.

Cause
If stones etc. remain trapped between dual tyres, this may lead to severe sidewall damage or to a break in the casing.

Recommendation
Regularly check for and remove any trapped foreign objects. To do this, tyres must be deflated and in some cases the outer wheel removed.

Cause
A sharp-edged foreign object penetrates in a localized area and causes the casing to rupture.

Recommendation
Tyres damaged in this way cannot normally be repaired; they must be replaced.

Cause
Driving with insufficient tyre pressure. Excessive flexing and the heat then produced may cause complete of loss of tyre pressure:

• Penetrating nails or similar sharp objects
• Leaking valves
• Defective tubes and bead flaps
• Hairline cracks in the rim(for tubeless tyres)

Recommendation

• Check tyre pressure regularly.
• Establish cause of loss in tyre pressureand rectify.
• Use only new tubes and bead flaps.

Cause
Frequent bumping into and scraping along curbs. Sometimes carcass damage may result.

Recommendation

• Check the sidewalls regularly.
• If the tyre shows excessive wear, fit the wheel to a less endangered position or rotate the tyre on its rim.
• Replace the tyre when the damage goes
  as deep as the casing.
• Use a special tyre if necessary, e. g. for
  buses.

Cause
Excessive warmth on brakes and rims as a result of sustained braking or malfunctioning brakes.

Recommendation

• Regularly check the brakes and the braking system.
• Use retarder or constant throttle.

Cause
Using incorrect or sharp-edge fitting tools.
Fitting without the aid of lubricants.

Note
Excessive warming of the brake drums, leading to hardening of the beads, can set the stage for this type of damage.

Recommendation
Follow fitting instructions.

Cause
Locally deformed rim or corrosion of the rim flange.

Recommendation

• Check the rim for damage and replace if
  necessary.
• Remove any rust from the rim and renew
  protective coating before fitting.
• Use suitable fitting lubricants (e. g. CONTIFIX).