Also like World Superbike, many of the endurance teams run works bikes or have significant factory backing and all the bikes including the pure privateers are heavily modified from the basic road specification. Often the bikes are based closely on the preceding season's World Superbike specification. For a machine to survive 24 hours of continuous racing with up to three different riders, the requirements are very different from those of short circuit racing where performance is more important than longevity. An endurance bike will generally sacrifice some performance for increased durability and reliability. The SERT GSX-R750 Suzuki, for example, runs slightly softer cam timing and a slightly lower compression ratio than the WSB spec engine and as a result the SERT bike is 10 bhp down, at 150 bhp.
Weights are also slightly higher as the bike has to carry lights, a starter and a generator.
As a result, the SERT Suzuki is noticeably slower than the 1998 WSB bike. The engine build will naturally feature many modifications from stock in order to both lighten and strengthen componemts. Another major difference is the fact that the bikes cannot be individually tailored to individual riders as three different riders will be piloting the machine over the course of a race. In short circuit racing, the bike set up will be dictated by rider preference for brakes, suspension and handling. This level of personalisation is obviously not possible for endurance bikes where a consensus set up that suits all the riders must be achieved.