The modern dynamometer is basically a roller drum of a known mass with some means of restraining a motorcycle. It is also fitted with cooling fans and exhaust extraction.
Sensors accurately measure the time it takes the bike?s wheel to accelerate the roller and check for wheel spin, and use this information to calculate rear wheel horse power and torque values. The clutch is then pulled in and the electronics measure the drums deceleration, allowing a crankshaft figure to be ascertained. Our dyno also incorporates a weather station which takes into account atmospheric conditions when working out a DIN figure. We can also measure the air/fuel ratio during a test by means of an exhaust lambda probe.
Whats Torque and Horse power ?
Torque is the turning force of the crankshaft or rear wheel and horse power is that turning force x its speed. The lower more horizontal line on a dyno graph is the torque and the upper more diagonal line is the hp.