D - INTRODUCTION The bikes are all clutch driven and they have also been privy to technological improvement. The clutches used are a 'dry' clutch. It is built from layers of carbon or fibre drive plates that ride against metal or rubber plates. The clutch spins at an amazing rate and warms up quickly. The key to any speedway start is the launch from the start line. The clutch play a highly important role in this to give optimum drive. The clutch is held on the crankshaft with special headed screws and specially designed holders. The outer plate is required to have a raised edge cover that protects the rider from the immense spinning action. The older clutches were held by tree screws, whereas the newer style are 6 screws which allow more control over the setups. These screws are tightened to ensure that the rear wheel will be released at the drop of the clutch. Depending on the riders gating style. The clutch will need to be set up for slip and drive. A rider will not let go of the clutch fully upon the start, if they are in need of more grip to the back wheel. They will what is known as 'slip' the clutch, which means that using the two middle fingers of the left hand, you hold the clutch and physically tweak it until optimum power is found, then the clutch is released fully by the time you are in the first corner. Many hours of practice is needed to really understand the effects it has on the bike, and its consequences between winning and losing a race from the start line.