I'm thinking of switching my five-speed to a six-speed.What is the difference in a direct-drive and an over-drive? Also, is my stock 88 motor capable of using a sixth gear?

 

Doesn't BAKER already have a 7 speed? if so, mine as well get the 7!

 

the baker direct drive 6 and 7 speeds have a final drive of 1:1. you won't notice much of a difference if any from the factory 5 speed. the overdrives are somewhere in the neighborhood of a .69:1 ratio. harley change the gearing between the tranny and the engine to drop the rpms with the 6 speed trannies.
hope this helps.

 

your stock 88 probably wont make enough torque to use a taller geared 6th up any decent sort of hill in my opinion. I would just run the 5 speed if I was you.

 

Sorry but I dis-agree abit here. I had a Baker DD6 put in just before going to Daytona for Bike Week. 70mph on the highway at 2700rpm or so, 75mph at 3000rpm or maybe a little less. If you are going to run some highways and tour a little it is a good thing to have. Running over 65mph the motor pulls fine.

 

dd= direct drive 1to1 motor to tranny
od= .86 to 1 or some combo like that motor to tranny

I will be putting a 6sp od in my 99 ultra to reduce 75mph rpms I do have a well built 95in cammed motor though

 

A Baker 6 speed is not a 1:1 ratio set of gears. It's a true overdrive. Therefore you do get lower rpm at higher speeds, and it's definitely an advantage if you are doing a lot of touring/long distance riding. HD's 6 speed is a 1:1 ratio, and is NOT an overdrive. Therefore you don't really see a significant difference in rpm reduction in 6th as you would with a Baker. Check out their website. http://www.bakerdrivetrain.com/

 

Milo has the best info but the long form.

The OD 6 retains the 1st-5th ratios with a .86 6th (OD) giving you an overall ratio of 2.7:1
The DD6 uses a 28 tooth compensator sprocket and different transmission gearing. With the bigger comp sprocket, the gearing of the trans mimics the 5 speed ratios with 6th being 1-1 or a overall ratio of 2.8:1
Stock overall ratio on your bike is 3.15:1 so either transmission will reduce cruse engine speed.
I personally went with the SE 6 speed for 2 reasons. Cost at the time ($1995 -10% but there are 20% off dealers) and most of my miles are in the 50-60 mph range so I wanted to keep 5th direst drive to reduce ware and tear on the transmission and the reduced noise and power loss still running through 5th on a DD6. I was also Leary about the .86 OD on the OD6 but felt that the .89 on the SE was a better choice with a overall ratio of 2.8:1. So far I am very pleased with my choice. Baker makes quality products, I would only question weather you want to run the OD6 (5th being 1:1) or the DD6 (6th being 1:1)

 

I'm still a bit confused, what I want is to be cruising at 75 at the same engine speed as what I am running at 65 now, which seems to be the sweet spot on my motor.I would like to hit 70 in 5th gear and shift up to 6th gear and be cruising at 75.

 

DD6 Gear Ratios
Top Gear RPM : 5-Speed vs. DD6 MPH
5-speed RPM in 5th DD6 RPM in 6th
65
2945 2528

70
3172 2723

75
3398 2917

80
3625 3112
Calculated data based on a 24/37 primary, a 32/70 secondary, and a 25” rear tire.


from baker web site