Direct replacement of the Cruise Drive Harley-Davidson factory 6-speed. The 7th gear enables the motorcycle to make full use, by the way of gear ratio management, of the torque and power put out by the 96 ci, 103 ci and 110 ci motors. Unlike the stock mainshaft which includes 1st through 4th gears, the DD7 is lightweight and only includes the small 1st gear, minimizing the shift clunk. Features a shortened 1st gear and tightened all other gears for a smooth and powerful riding experience with continuous acceleration from 1st to 4th gear. Shift smoothness is achieved by use of a new linear roller ball detent which is part of the supplied billet top cover. Comes ready to slide in the bike, no case modifications, shimming of the gear set or adjustments required. 7th main drive gear, main drive gear bearing, main drive seal are all included to replace 6th main. Includes new main drive gear bearing and seal, polished door, door gasket, side cover gasket, top cover gasket and self-adhesive DD7 side cover emblem. Bearing door is manufacturered from 6061-T6 Aluminum and features wider bearings and a bearing retainer plates instead of the stock style snap rings. DD7 door bearings are 28% wider than stock. Made in the U.S.A..