For winter cycling on icy roads. The spikes are arranged, not in the center of the tread, but alongside it, in the area of greatest contact pressure. By lowering the air pressure the tire achieves optimal grip on icy roads. In normal road conditions the rolling resistance can be reduced with additional air pressure.
Note: All Schwalbe spikes have an extremely hardwearing tungsten-carbide core with a base of fully galvanized steel.
In order to ensure that spikes are permanently fixed, tires should be run in for about 25 miles (40km) on asphalt, while avoiding any fast acceleration or heavy braking.