Fine-tune the speed and acceleration of the Savage Flux HP with a selection of tough metal pinion gears and spur gears! Use a larger pinion gear or smaller spur gear for higher top speeds, or use a smaller pinion gear or larger spur gear for increased acceleration. #100911 PINION GEAR 12 TOOTH (1M / 5mm SHAFT) #100912 PINION GEAR 13 TOOTH (1M / 5mm SHAFT) #100913 PINION GEAR 14 TOOTH (1M / 5mm SHAFT) #100914 PINION GEAR 15 TOOTH (1M / 5mm SHAFT) #100915 PINION GEAR 16 TOOTH (1M / 5mm SHAFT) #100916 PINION GEAR 17 TOOTH (1M / 5mm SHAFT) #100917 PINION GEAR 18 TOOTH (1M / 5mm SHAFT) #100918 PINION GEAR 19 TOOTH (1M / 5mm SHAFT) #100919 PINION GEAR 20 TOOTH (1M / 5mm SHAFT) #100920 PINION GEAR 21 TOOTH (1M / 5mm SHAFT) #100921 PINION GEAR 22 TOOTH (1M / 5mm SHAFT) #102086 PINION GEAR 23 TOOTH (1M / 5mm SHAFT) #102087 PINION GEAR 24 TOOTH (1M / 5mm SHAFT) #102088 PINION GEAR 25 TOOTH (1M / 5mm SHAFT) (standard) Also available are Heavy Duty spur gears: #102092 HEAVY DUTY SPUR GEAR 43 TOOTH #102093 HEAVY DUTY SPUR GEAR 44 TOOTH (standard)