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TECHNICAL GLOSSARY

UNDERSTANDING THE VARIOUS MARKINGS AND OTHER TECHNICAL INFORMATION

MARKING IN MILLIMETRES

Example: 650x32A (32-590)

  • The first number (650) denotes the overall diameter of the tyre in millimetres.
  • The second number (32) denotes the tyre section in millimetres.
  • The letter A indicates that the rim is a 590 mm.


MARKING IN INCHES

Example: 26*1 3/8 * 1 1/4 (32*590)

  • The first number (26) indicates the overall diameter of the tyre in inches.
  • The second number (1 3/8) denotes the tyre height in inches and fractions of inches.
  • The third number (1 1/4) gives the tyre section in inches and fractions of inches.


Special case of marking in inches:

Example : 28*1 5/8 * 1 1/4 * 1 1/8 or 700 C Course or 32-622

  • The first number (28) denotes the tyre's overall diameter in inches.
  • The second number (1 5/8) gives the height of the tyre in inches and fractions of inches.
  • The third number (1 1/4) indicates the tyre section in inches and fractions of inches.
  • The fourth number (1 1/8) denotes the width of the rim which accommodates this tyre in inches and fractions of inches.

 

ETRTO STANDARD MARKING

Example: 32*590 (650*32A)

  • The first number (32) indicates the tyre section in millimetres.
  • The second number (590) gives the tyre diameter in millimetres.

 

GLOSSARY

  • ETRTO : European Tyre and Rim Technical Organization.
  • The Gum Wall (GW) sidewall is coated with a layer of rubber to give it stiffness and protect it.
    Advantage : resistance to sidewall tears.
  • The Skin Wall (SW) sidewall allows us to make out the texture of the casing through its transparency.
    Advantages : lightweight, flexible and efficient.
  • Overlap : Central part of the casing.
  • Weight : The weights stated are given as a guide with a tolerance of plus or minus 7 %.
    This variation is due to the natural elements inherent in the construction of tyres.
  • P.S.I.: Pound Per Square Inch or BAR or Kg/cm².
  • Section : Width of the inflated tyre from sidewall to sidewall.
  • Shore is a unit of measurement ranging from 0 to 100. This unit measures the hardness of elastic products. (From 0 soft to 100 hard).
  • TPI : Threads Per Inch- number of threads per inch.
    This measurement represents the density of cords in the tyre casing. The greater the density, the lighter, more flexible and mobile the tyre.
  • Wire bead (WB) : Being made of steel wire, they are cheap.
  • Flexible bead (FB) : Invented and perfected by MICHELIN, they are made of aramide (e.g. Kevlar®). They are lighter and allow the tyre to be folded.
  • Tubeless : Tyre fitted without inner tube. It needs specific rims. The advantage of the tubeless tyre lies in its ease of implementation. As the rim is already fitted with a valve, the tyre just needs to be fitted and maintained.
  • Tubeless Ready (TLR) : Tubeless Ready tyres can be fitted without an inner tube provided that a tubeless wheel is used, the maximum pressure is not exceeded, sealant is added and the tyre pressure is checked before each ride.

FITTING MOUNTAIN BIKE TUBELESS TYRE

How to Mount a Tubeless* MTB Tire - Michelin Bike

FITTING A MICHELIN COMPETITION TYRE

How to Mount a Michelin Road Bike Tire - Michelin Bike

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