Glossary

Asymmetric tyres In MotoGP these are only available as rear tyres. Asymmetric slicks comprise a harder compound in one shoulder and a softer compound in the other designed for circuits which create higher tyre temperatures in one shoulder than the other, usually because of an imbalance of right and left-handed corners

Bead Serves as an anchor to hold the tyre securely to the wheel rim

Belts Belts are one of the core components of tyres. They may be steel, nylon, polyester or other such materials, and form a literal belt around the tyre to strengthen the tread area and to make the tyre puncture resistant

Camber angle Measured in degrees, camber is the inward or outward tilt of the wheel at its uppermost point when compared with the true vertical line at the centreline of the wheel. In MotoGP, camber angle is the same meaning as lean angle. Generally, the greater the lean angle, the higher the lateral force and so the more demanding on the tyres

Carbon black A molecular structure found in all racing tyres, carbon black is a black powder substance produced by burning oils in a furnace. It provides strength and also produces the familiar black colour of tyres. There are hundreds of kinds of carbon black and each will produce a compound with certain properties: improved traction, hardness, wear and so on

Compound Formed by a mixture of various elements used by tyre manufacturers to produce the surface layer of a race tyre, the compound’s properties vary with the exact blend of ingredients. It is the compound that is in contact with the track and therefore one of the major factors in deciding tyre performance, being a trade-off between outright grip and durability

Construction The way in which the component parts (belt, cords, tread, sidewall) of a tyre are constructed determines its ability to absorb shocks, transmit traction and braking forces and to provide strength to contain inflation pressure. The nature of a tyre is dependent upon the way in which the component parts are laid and assembled

High-side This is a type of crash in bike racing which the rear tyre loses grip, either because of slippery conditions, insufficient temperature and too much throttle applied by the rider or a number of other reasons, and slides sideways. The rear then grips and tries to snap back into line with the front wheel, and the force often throws the rider off

Low-side The opposite to a high-side, in a low-side crash the front tyre will most commonly lose grip mid-corner, either because of excess corner speed, insufficient temperature and too great a lean angle or a number of other reasons, and the bike will slide out from beneath the rider

Polymers One of the core components of rubber, from one of two main groups: natural or synthetic

Sidewall The sidewall is the most important element in transferring engine power to the tyres as it connects the wheel rim to the tyre tread, and therefore the track surface

Stagger To give cars a natural turn to the left on oval courses within IndyCar, larger diameter tyres maybe placed on the outside (driver’s right) of the vehicle. The difference is known as stagger

Tyre warmer/blanket A warming device designed to maintain a uniform temperature throughout the tyre. Used in MotoGP but not in IndyCar