Originally Posted by gtrman66
Sounds cool. I would save your money on the 6 speed. It doesn't give you anything you are looking for. Mine lugged in 6th even at 90mph. Maybe it was gearing, but I just don't think you'll need it. I say this after several EVO's and 1 with a 6 speed.
The 6 speed may not be necessary, and I know I'd never use it around town and would only use it on the highway for a lower cruising RPM, which I wanted for the built up motor for longevity.
I was still on the fence about it. I talked to the guys at Baker and they recommended the DD6. I started crunching numbers on it to figure out, other than how the gears are set up in the case, what the difference would be.
With the DD6 on a softail, you would swap the compensator from the stock 25 tooth to one that's 28 tooth, which makes the DD6 effectively the same gear ratio as the OD6 (DD6's 6th gear is direct 1.0, but the 28 tooth comp makes it effectively .86). In all the numbers I crunched (using this calculator
), the effective gear ratio of all gears (due to the change in primary ratio) of the DD6 is the same as the gear ratio in the OD6 (with stock primary ratio), but the overall ratio (engine to rear wheel) is different (one is 2.9 and the other is 3.-something) and the DD6 causes a lower RPM at any given speed than the OD6.
But anyway, 99% of my riding is not touring, though getting from town to town here can take 30+ minutes with 20 minutes of that being on the highway at 70 mph (which is exactly when I start looking for another gear).
I knew full well that I wouldn't use the 6th gear much. I was mainly on the fence about it not because of price, but whether it would hinder performance or change the feel. And I don't want to go through the labor of swapping the guts. The SE 6-speed transmission for mine is $2,100 and the DD6 builders kit guts are $2,495.00. I couldn't find online the gear ratios for that specific SE 6 speed, though one place I saw pegged the 6th gear at .89 (which is a less drastic overdrive than the .86 of the Baker, but apparently uses the same 2.95 or whatever first gear as the Baker as best I can tell). Even though Baker recommended the DD6, I wasn't sure if they understood what I was asking about (I don't want to sacrifice acceleration for better mpg and lower cruising RPMs).
So, I looked at just swapping the transmission out as a whole and it's around $3600 for the Baker DD6 complete (fully assembled case) with everything I need (speed sensor recalibration module, the new compensator and different pitch chain, etc). I'd personally pay that much to just swap the whole transmission instead of taking one apart and putting new guts. I both am and am not really worried about money. There's some instances where I try to save and others I am not worried about it. As long as I have enough for an emergency (which I now do), I am fine.
What 6 speed did you have in it, do you recall? And what was the model and year and build on that Evo? I was reading about the Evo softails and I think in 1992 or 1994, they changed the overall ratio by changing the primary ratios. I think before the primary had a more aggressive ratio, like 24/37 or something? Maybe the ratio from transmission to rear wheel was different too? I don't remember at the moment, but I do know mine stock is 25/36 in the primary.
Just found the thing I was reading about it (https://www.hotbikeweb.com/motorcycl...-basics#page-5
Starting in 1995, all Evolution Softail Big Twins were shipped from the factory with a 2.92:1 final drive ratio (a 1.44 primary ratio multiplied by a 2.03 secondary ratio equals 2.92) while all other Evo Big Twins shipped with a 3.15:1 final drive ratio (a 1.44 primary ratio multiplied by a 2.19 secondary ratio equals a 3.15). Most 1993 and earlier Evo Big Twins came with a 3.37:1 final drive ratio. The pattern we see here is that 1995 and later Softails have a higher (lower numerically) final drive ratio (2.92:1) than the other models. This means the engine's crankshaft turns 2.92 revolutions for every revolution of the rear wheel. All things being equal, this gives the Softail less acceleration than the other models but requires less rpm at highway speeds for smoother running.