Set: Gear Optimization Set - the set includes: Special Bolt for Shift Drum screwed, Optimized Shift Lever, and Needle Bearing for Shift Drum Special Bolt for Shift Drum screwed - easy installation of the shift drum, no pressing required - easy adjustment of the axial play of the shift drum - bearing washer is omitted, finished on the bolt - improves shifting behavior - Made in Germany - hardened - perfect for racing use - retaining ring 12x1 DIN 471 is omitted - securing of the shift drum is done by a screw with a rosette washer - is inserted and screwed into the left engine half - engine must be opened for installation Note: Insert bolt with high-strength thread locker into the housing! Optimized Shift Lever - optimized shift lever for shifting - reduced play between shift drum and shift lever - better adjustability and shifting accuracy - pin on the shift lever is turned down and a drill bushing is pressed on - additionally secured with thread locker - pin is exactly 8.00mm outer dimension through the drill bushing, hardened and ground Note: Shift lever is designed for 5-speed shift drums or replica 3 or 4-speed shift drums. When using on 3 or 4-speed DDR shift drums, the groove must be checked before purchase. Partially, the milled grooves are under 8mm and thus the shift lever cannot be mounted. For this, a replica shift drum can be used, which have a groove width of about 8.1mm. Needle Bearing for Shift Drum - reduces the radial play of the shift drum - improves shifting, more direct and easier - is pressed into the shift drum - ideal for 5-speed gearboxes - fits for screwed shift drum bolts and shift drum bolts - last picture shows installation location on the shift drum bolt - shift drum bolt not included Note: The needle bearing is adapted for 5-speed shift drums from MZA. When used in other shift drums, such as 4-speed DDR, adjustments may be required. Check shift drum bolt! DDR shift drum bolts vary in dimensions and may therefore have a diameter of over 15.0mm at the bearing point. The shift drum bolt must not exceed 15.0mm, if necessary, use replica shift drum bolts or screwed shift drum bolts.