Many riders will have at one time or another noticed a thin dark line running around the circumference of their motorcycle tyre.
Most will have paid it little attention, if any at all, although for some it can obviously be of concern if they don’t know what it actually is.
Well, first of all it’s good to know that a line like the one shown on the Bridgestone Battlax T30 to the right is nothing to worry about.
Motorcycle tyres have a lot of different materials used in their compounds, and one of those materials is silica. The use of silica in a tyre’s rubber compound helps to improve warm-up times, and therefore improve grip in both cold and wet conditions. The only problem with silica is it’s a very good electrical isolator.
Silica rich compounds build up a static electrical charge as you ride. On occasion this can be enough to give you a small electrical shock as your foot hits the ground, giving the electrical charge a route to earth.
This thin dark line is a silica free band of “antenna tread” which actually helps to dissipate the static electricity as you ride, rather than letting it build up to give you a nasty shock at the next junction or set of traffic lights. It’s common in motorcycle, car and truck tyres – although it’s much easier to see on a motorcycle tyre.
The visible line may fade during the life of the tyre as it wears, but it’s there to help you!
