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.