Riders are not always travelling at full speed or at a specific radius. Most events have riders all over the track. Team races (like the madison) have some riders at speed and others riding more slowly. In match sprints riders may come to a stop by performing a track stand in which they balance the bicycle on the sloped surface while keeping their feet locked into the pedals. For these reasons, the banking tends to be 10 to 15 degrees less than physics predicts. Also, the straights are banked 10 to 15 degrees more than physics would predict. These compromises make the track ridable at a range of speeds. From the straight, the curve of the track increases gradually into the circular turn. This section of decreasing radius is called the easement spiral or transition. It allows bicycles to follow the track around the corner at a constant radial position. Thus riders can concentrate on tactics rather than steering. Bicycles and track design Bicycles for velodromes, better known as track bicycles, have no brakes. They employ a single fixed rear gear, or cog, that does not freewheel. This helps maximise speed, reduces weight, and avoids sudden braking while nevertheless allowing the rider to slow by pushing back against the pedals. Modern velodromes are constructed by specialised designers. The Schuermann architects in Germany have built more than 125 tracks worldwide. Most of Schuermann's outdoor tracks are made of wood trusswork with a surface of strips of the rare rain-forest wood Afzelia. Indoor velodromes are built with less expensive pine surfaces. The track is measured along a line up from the bottom. Olympic and World Championship velodromes must measure . Other events on the UCI International Calendar may be held in velodromes that measure between and inclusive, with a length such that a whole or half number of laps give a distance of . The velodrome at Calshot, Hampshire, UK is only and has especially steep banking because it was built to fit inside an aircraft hangar. Forest City Velodrome in London, Ontario, Canada, is the world's shortest at . Built to fit a hockey arena, it too has steep banking. The smaller the track, the steeper the banking. A track banks around 45°, while a track banks around 32°. Some older velodromes were built to imperial standards. The Dick Lane Velodrome in East Point, Georgia USA, is . Velodrome tracks can