The Sport range of spares provides everything you need to fine tune a Scalextric car to get the maximum performance from it on the track These Sport pinion gears are suitable for use with most standard Scalextric SP motors 18 000 rpm as well as the yellow C8421 20 000 rpm orange C8422 25 000 rpm and blue C8423 30 000 rpm replacement SP motors Contains 8 9 10 11 and 12 tooth gears