DD6 -2000 - up Softail Direct Drive 6 spd.

DD6 90-97 Softail Direct Drive 6 Spd. In 1996 we started work on the now legendary BAKER 6-speed Overdrive (OD6). We morphed the factory ?1:1? 5-speed design into a 6-speed variant, similar to what American car companies had done in the 60?s with their ?1:1? 4-speeds. The overdrive variant retained the same gear ratios as that of a stock transmission but gave you that added top end gear for highway cruising. Fast forward to the 21st century with our patented DD6. We have done what the car companies wish they could do. Our new DD6 is a 6-speed with a 1:1 top gear, thus the name Direct Drive 6-speed. Because of powerflow through the transmission, the 1:1 gear is always the most efficient gear, typically 99+% efficient. Meaning, for every 100 ft/lbs of torque that goes into the transmission, 99ft/lbs of torque comes out of the transmission and goes to the rear wheel. To compare, the 6th gear in an overdrive unit is around 92% efficient. DD6 was born because it made sense that the gear in which you spend the most time should be the most efficient. However by going to a 1:1 6th gear we lost the benefit of RPM reduction while cruising on the highway. No problem. We have ?OVERDRIVEN? the primary drive to adjust the overall drive ratio by using a 28-tooth compensating sprocket in place of the stock 24/25-tooth sprocket. The result is a 6-speed that is exactly, ratio wise, like the 6-speed Overdrive (OD6). The analogy goes like this. Late-model Corvettes have a 6-speed in which 4th gear is 1:1 and 5th and 6th are overdrive gears. The rear end axle ratio is 3.73:1. If that car magically had a transmission with a1:1 6th gear, the rear axle ratio would have to be ?adjusted? to a 2.08 ratio to keep ratios equal. This fictitious car would go down the road exactly the same as the production overdrive version, except the fictitious car would get 7% better fuel efficiency on the highway and have a higher top end speed. DD6 Features: Full width BAKER ground gears finished by diamond coated tooling Helical 4th, 5th, and 6th gears for silent operation Fixed spindle shift drum for smooth, low inertia, drum indexing Redundant neutral detent for positive neutral finding Chrome trap door with engraved DD6 logo Anti-overshift ratchet pawl included By design, the 28 tooth compensating sprocket yields 14% more starter system torque. Longer primary chain included. Available for all 1990-up Big Twin applications, see the catalog or call for part numbers. ----------------------------------------------------------------------------