This paper describes the design and analysis of a lightweight crankshaft for a high speed racing motorcycle engine. It covers the evolution of the crankshaft from the baseline, with rated speed of 14000 rpm, to the final design with rated speed of 16000 rpm. The lightweight crankshaft is compared with the baseline design in terms of the following criteria.

• Balance
• Mass and rotating inertia
• Main bearing loads and oil film thickness
• Torsional vibration
• Stress and fatigue safety factor

SAE 2007-01-0265