# Tyre Knowledge

Tyre Construction

Differences and Advantages

There are four different tyre constructions available:

  • Bias belted tyres
  • Breaker tyres
  • Crossply tyres
  • Radial tyres
Tire construction of the radial tire ContiRoadAttack 4

Bias belted tyre

The bias belted tyre is the precursor of the radial tyre. Whilst the casing is still crossply in design, the tyre features a belt, usually made from Kevlar. The bias belted tyre can be recognised by the B (=bias belted) in the designation on the tyre sidewall.

Typical designation:

150/70 B 17 M/C 69Q TL

Tire Construction - Bias belted tire

Breaker tyre

The breaker tyre originated from the crossply design, to provide a tread area which was effectively reinforced from the inside, giving the tyre a longer service life through reduced transverse slip and making it less prone to failure. Material used: usually rayon or nylon fabric. Normally the breaker and casing feature the same material.

Typical designation:

130/90 - 16 M/C 73H TL Reinforced

Tire Construction - Breaker tire

Crossply tyre

On today's market the crossply tyre is the "classic" design. Its advantages are its simple structure and its sturdy sidewalls, which particuallary in off-road use offer many benefits (impact protection). Crossply tyres have a maximum design speed of 150 mph. Material used: usually rayon or nylon fabric.

Typical designation:

4.00 - 18 M/C 64H TL

Tire Construction - Crossply tire

Radial tyre

Radial tyres feature a casing angle of approx. 90° to the circumferential direction (direction of travel) and a belt angle of 0 - 25° approximately. The belt, located under the tread area, gives the tyre stability and permits far higher speeds, as the centrifugal force deformation is subsantially lower. Reduced material thickness in the sidewall section means the tyre heats up less and the high speed strenght is futher increased.

In terms of riding dynamics, modern motorcycles are geared to radial tyres. As an example: a 4.00 - 18 M/C 64H TT tyre "grows" by approximately 2 cm on average at a speed of 131 mph, whereas a comparable radial tyre only expands by a few millimeters. The radial tyre can be recognised by the R in the designation on the sidewall of the tyre.

Typical designation:

190/50 ZR 17 M/C (73W) TL

Tire Construction - Radial tire