uys riding anything older than a 2007 Harley-Davidson are starting to feel left out of things. The new Harleys, and the ‘06 Dynas which introduced it, come factory-standard with a 6-speed transmission. The 5-speed boxes in all the other Twin Cams seem a little antiquated, but Baker has the fix and it doesn’t involve a trip to the dealership for a new motorcycle. It’s the DD6, the Direct Drive 6-Speed. This bolt-in update turns those 5-speeds into a genuine 6-speed overdrive transmission.
     And there’s more. That Baker DD6 conversion, arguably, will result in a 6-speed overdrive that’s better than the factory’s. It’s stronger and certainly quieter than the new OE Harley trans, which can howl like a banshee in 5th. The DD6 has none of that. With its quietly efficient gearing it’s a real overdrive transmission, too. At 70 mph the old 5-speed would have the engine turning 3,172 rpm; with the Baker DD6 that’s dropped back to 2,723.
     Baker has accomplished this by juggling around the primary drive ratio and the transmission’s gear ratios, starting with a 28-tooth drive sprocket that overdrives the transmission. The gear ratios in 1st through 5th were dropped 14-percent to make up for that change. Overall, they’re pretty much as they are in a stock Harley transmission, great for low-end acceleration. But the DD6’s top gear, 6th, is an ultra-efficient 1:1 direct drive through the transmission and with that overdriven primary becomes an overdrive. Baker has used smooth-meshing, quiet-running helical-cut gears in the 4th, 5th and 6th gear positions, too. The transmission is almost silent and vibration free. The DD6 also features Baker’s “redundant neutral system” to more easily locate neutral.
     The Direct Drive 6-Speed is available as a retrofit “Builder’s Kit” and installs in any existing 5-speed case from ‘90 on. It’s available as a completely assembled unit in a Baker case, too. And even packing that one more gear the DD6 is no wider then a stock Harley 5-speed so there are no worries about oil-spout spacers or modified exhaust systems and brackets. The DD6 is in-stock now at Drag Specialties.