IV - THE MAIN PROBLEMS The 7 main defects
Damage
Impact
crown sidewall
DESCRIPTION Crown damage with or without puncture and/or tearsand splits. Localized breaking.
CAUSES External aggression either by running over sharp/blunt objects or by rubbing against a foreign body.
DEVELOPMENT Damage to a tyre by running underinflated, breakage of plies, product delamination.
CHECKS / ADVICE Check conditions of use. Check pressure used. Replace the product(s) concerned if the damage is extensive and has reached plies or the carcass.
DESCRIPTION Damage to sidewalls with or without puncture instead of perforation and/or tears.
CAUSES External aggression either by running over sharp/blunt objects or by rubbing against a foreign body.
DEVELOPMENT Rubber and/or plies broken on the sidewall, running underinflated.
CHECKS / ADVICE Check the conditions of use. Check pressure used. Replace the product(s) concerned if the damage is extensive and has reached plies or the carcass.
crown sidewall
DESCRIPTION Impact with plies broken on the crown. Evidence of impact are generally found on the tread.
CAUSES External aggression by running over sharp/blunt objects.
DEVELOPMENT Rubber and/or plies broken on the sidewall, running underinflated.
CHECKS / ADVICE Check conditions of use. Replace the tyre. Examine the other tyres on the vehicle.
DESCRIPTION Cuts extended to the carcass, visible plies with or without broken cords. Pinching impact. Immediate break without pinching.
CAUSES Impact or pinching of the sidewalls after running over a pothole or mounting a kern for example.
DEVELOPMENT Rubber and/or plies broken on the sidewall, running underinflated.
CHECKS / ADVICE Check conditions of use: Replace the product(s) concerned if the carcasses
are damaged.
Technical data
MICHELIN 2wheeL - 179
Useful tip When making visual checks pay particular attention to the tread area and the sidewalls. Look for unusual, excessive, or uneven tread wear, foreign objects, bulges or deformation, signs of penetration, cracking of the rubber or any deterioration or damage.