Baker DD7 Transmission. Way More to It Than An Extra Gear.

Published by Cyril Huze

The Baker Direct Drive 7-Speed was developed as a direct replacement of the Cruise Drive Harley-Davidson factory 6-speed to improve it in many ways besides just adding another gear. The DD7 is all about gear ratio management. The gear ratios leave you the rider, with the experience of smooth, crisp, continuously pulling acceleration from 1st all the way through 4th gear. Then you are able to start getting into the cruising portion of the program in gears 5th to-7th. No big drops in RPM from one gear to the next or lugging the motorcycle off of a stop light, just smooth, uninhibited acceleration.

Baker Drivetrain did not make this DD7 transmission just a deep overdrive. The 1st gear is shorter (numerically larger) for easier launches off the line. They improved the smoothness and crispness of the shifting by reducing the mainshaft mass by only having 1st gear be a part of the shaft, rather than 1st to 4th gear like on the stock unit. The factory 6-speed incorporates 1st through 4th gears as an integral part of the mainshaft and weighs 5.58 lbs. The DD7 incorporates 1st gear only and weighs 2.98 lbs.  This is a 2.6 lbs weight difference at 3000 rpm and translates into a huge difference in inertia, which is what makes the factory 6-speed go CLUNK every time a shift is made

For shift smoothness, Baker sets a new standard in shift quality by borrowing the linear roller ball detent technology from their TorqueBox transmission.  This premium detent system is part of the top cover assembly that is included in the kit. To eliminate gear noise they designed the DD7 with a 5 degree helical 1st gear pair, straight cut 2nd and 3rd for strength, and 18 degree helicals for 4th, 5th, 6th and 7th for noise control. Baker DD7 fitment: 2007-2009 Softail, 2006-2009 DYNA, 2007-2009 FLT-FLH. Baker Drivetrain.