Malossi White Reinforced Clutch Spring. Helps your clutch engage better, with less jerkiness on take-off. This is the most popular replacement clutch spring for BMW Scooters in Germany.

VARIABLE-SPEED DRIVE ADJUSTER SPRING
Silicon-steel springs with high carbon content, heat-treated, dynamically balanced, kiln painted, designed and calculated for each specific application. 

BMW BMW C Sport 600
BMW BMW C GT 650