- Tire presentation
- Tire markings
- General information about tires marking
- Dimensional equivalence
- Mounting, dismounting, running in for a tyres
- Pressure general
- The main problems handling difficulties
- The main problems threats to the tire
- The main problems rubber breakdown in the cold- track specificities
- The main problems the 7 main defects
- Tire life tire repair advice
- Tire life tire age and performance
- Tire life storage advice
TIRE PRESENTATION
The Anti-Static Strip
A unique feature necessary in a tire
- A vehicle is charged with static electricity and must be able to discharge this electricity into the ground. Since the tire is the only point of contact between the vehicle and the ground, there is a regulation in this respect governing the minimum level of conductivity of tires.
- When carbon black is used as a reinforcement filler, tires normally have an acceptable level of conductivity.
- When other reinforcement fillers are used, such as silica, the level of conductivity may decrease. It then becomes necessary to apply design features to restore conductivity to an acceptable level.
TIRE MARKINGS
How to read a tire sidewall
General information about tires marking
Dimensional equivalence
All types of diagonal architecture tires
Mounting, dismounting, running in for a tyres
In all cases, it is essential to refer to the technical instructions of the tire manufacturer, vehicle manufacturer and wheel manufacturer, as well as the user manual for the tire-fitting machinery or equipment.
If the rim shows evidence of damage, the tires must be deflated prior to removal of the whole fitmen
Replace your tire if the tire depth is at the level of the tread wear indicator (which complies with regulation at 0,8mm) ; you can easily find the tread wear indicators with the small Bibendum on the shoulder of the Michelin tire”.
Bedding
For On Road usage, new tires require a period of bedding in before normal use. Michelin suggests that riders start slowly and use gentle acceleration and braking and low lean angles to bed the tires in, gradually increasing the demands on the tires until you become accustomed to the performance of your new tires in conjunction with your motorcycle. We recommend at least 60 miles / 100 kms for this process. This applies to all our motorcycle and scooter tires.
For track usage tires (NHS and road legal), after NEW tires fitting, or at the beginning of each session , Michelin advises to
– With tirewarmers: maintain the temperature with a sufficient solicitation from the start
– Without tirewarmers: start slowly and use gentle acceleration and braking and low lean angles to bed the tires in, gradually increasing the demands on the tires until you become accustomed to the performance of your new tires in conjunction with your motorcycle.
For the rain tires (NHS), after NEW tires fitting, , or at the beginning of each session, avoid strong acceleration, breaking, cornering.
Then increase the running pace gradually in order for you to accustomed to the capacities of your tires
Pressure general
Adhere to the pressure recommended by the vehicle manufacturer, regularly checking that this is proving suitable for your particular use of the bike
Manufacturer tire pressures are carefully arrived at and are safe and effective, however the possibility exists that on rare occasions they can prove to be less than perfect.
If the tire starts to exhibit any signs of uneven or abnormal wear when using recommended tire pressures then seek expert advice.
Tire PRESSURE
If a tire is inflated when hot, the pressure must be adjusted in line with manufacturer recommendations. To be correct, you should be aware that the pressure may be around 0.3 bars higher than the recommended level when cold.
example:
• Hot tire pressure reading = 2.6 bar
• Recommended cold pressure= 2,5 bar
• What we should read = 2.8 bar
• Add 0.2 bar
Inflation with nitrogen
Does not mean that frequent pressure checks are not to be made. After checking the tire pressures do not forget to replace the valve cap which in addition to the valve body ensures an airtight seal.
Valve cap
A valve cap is essential to ensure a correct airtight seal. In fact, at high speed, the valve body can be pushed in by simple centrifugal force.
This leads to a loss of pressure and the risk is eliminated simply by fitting a valve cap.
The main problems handling difficulties
Handling difficulties defined
It is not always easy to determine the causes and origins of various handling problems. Handling problems may come from Tires (type of tire, incorrect pressure) and/or a change to the vehicle (accessory, load, etc.). tires are not always the cause.
When the tires are partly responsible for handling problems
The main problems threats to the tire
The three main threats to the tire are physical, environmental and human.
They are usually related to the inflation pressure, damage, the level of wear of the tread, weather conditions, maintenance, load conditions and speed, … etc.
With so many parameters involved, it is impossible to accurately predict the lifespan of a tire.
PHYSICAL
- Age
- Poor conditions of storage
- Wear and damage (punctures, cuts, impacts, cracking/ crazing of the tread/sidewall rubber, lumps and bulges, etc).
ENVIRONMENTAL HAZARDS
- Extreme temperature.
- Moisture
- Ozone
- Solvents, Hydrocarbons
- Fuel
- Chemicals
HUMAN
- Does not perform routine tire checks for wear or damage.
- Does not maintain proper tire pressure (under inflation or over inflation).
- Re-inflates a tire that has run flat or seriously under-inflated.
- Does not change a tire before it reaches the legal wear limit.
- Neglecting a change in behavior of the bike, loss of pressure, vibration, noise, ….
- Does not inspect a tire after a severe impact.
- Has an aggressive riding style.
- Uses tires of different sizes or types.
- Does not replace the valve when replacing a tubeless tire.
- Repairs a tire themselves rather than go to a tire specialist
- Temporary repairs that become a permanent solution.
- Mount a tire on a wheel that is damaged or distorted.
- Does not store tires correctly.
The main problems rubber breakdown in the cold- track specificities
The fundamentals
All rubber compounds used in tires have performance windows that fall within a range of temperatures.
- There is a low temperature threshold from which the rubber loses elasticity and becomes brittle. This can be as low as -55°C for some rubber compounds. This is called the breaking point.
- There is also a high temperature threshold from which the rubber becomes pasty/viscous. This is generally above 200°C. It is called the reversion point. The vast majority of our tires operate within these thermal limits without impediment.
Hypersport and competition tires
In competition and hypersport tires, the very high temperatures encountered (related to the very high levels of grip) require a specific blend of tire compounds to withstand them.
One consequence of this is that these soft compound tires have a break point of as high as 15°C.
Handling these tires at this temperature or lower may result in the tread or other area of rubber on the tire literally breaking. Care must therefore be taken to store the tires in appropriate conditions which avoid these temperatures. If this occurs, the tires should not be handled at all.
The main problems the 7 main defects
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.
Damage
Impact
Cracks
Splits / Crown
Graining (competition range)
Marble
Tire damage / Wear
Tire life tire repair advice
Tire life tire age and performance
Tire life storage advice
Temperature, light and certain chemicals or electrical equipment are known factors affecting ageing:
it is therefore essential that products are stored correctly.
DRY CONDITIONS
Store tires in a cool, dry room with natural ventilation to avoid condensation.
If outside, cover them with an opaque, waterproof tarpaulin.
LIGHT
Protect tires from UV rays (sunlight and artificial light).
TEMPERATURE
It must be below 35°C. Avoid direct contact with pipes, radiators and other direct sources of heat and cold.
ELECTRICAL EQUIPMENT, SOLVENTS, HYDROCARBONS, FLAMMABLE SUBSTANCES, CHEMICALS
Never store tires in a room where this equipment or these products are present.
STOCK ROTATION
First in, first out storage of tires should be organized.
SHORT-TERM STORAGE (<4 weeks)
Stack tires on pallets, preferably lying flat. Stacks should not exceed 1.2m (4 feet) in height.
Bead separators may be required to prevent tire beads closing up. After 4 weeks, the stacks should be reformed with tires piled up in reverse order. When fitted onto wheels, tires should be inflated when stored and kept in a vertical position or in only one layer on shelves.
LONG-TERM STORAGE:
Store tires vertically on shelves at least 10cm (4 inches) from the floor.
To prevent deformation, rotate slightly once a month.