I can buy a car for $2700.00...

But not with a 7-speed trans in it..... :icon_naughty:

I hear what you're saying but far as I know 1:1 is 1 to 1 doesn't matter how you spell it, or candy coat it.

LOL

The benefit of a 1:1 over an overdrive is that the 1:1 has lower power losses. The input shaft and output shaft are essentially locked together, so no losses between two gears, as an overdrive has. So a 1:1, even if overall gearing is as high as an overdrive would be, gives better fuel consumption, and also is quieter. I suspect that is why they have become popular.

In the pursuit of noise and emissions regulations, Harley and other manufacturers are using every tactic they can to keep legal. We have two cars with 7-speed auto trans at home. On a level road they click through the gears in very quick time, so the engine speed never gets very high and they are happy in seventh at as low as 1500rpm. So the car makers are doing much the same.

Harley went quite quickly from an overdrive 6-speed to direct drive, although the overall ratio for both is similar. That is just to chase down noise levels, while keeping engine speed down at the road speeds the noise tests are done at.

Well said, I believe that keeping the cruise drive 6 and Baker 7 speed trans as Direct Drive in top gear is crucial to power transfer, fuel economy, and reduced noise levels in engine and trans. Sure like that first gear ratio on the DD7. ndfrspd

Well I've learned some more about Tranny's. They are a complex component to any vehicle. I have worked in a tranny shop as a R&R worker. I never did understand the inner workings and how the heck those guys remembered how to repair every tranny that came in the shop. We had 6 lifts and did 30,000.00 a week in business 3 rebuilders and 3 R&R guy's.

I have to fix my own tranny before riding this year there is no 3rd or 4th gear, I am hoping it's just a bent fork not moving the slider enough, but who knows until the gear set is on the bench. Even with having to repair my own tranny I can't see purchasing the Baker7 2,700.00 is the deal breaker if it was 2,200.00 maybe.

I will be learning a lot more yet about the HD Tranny.

TY for correcting me.

I'm not sure I agree with this statement, though I hear it all the time from guys. The beauty of it that I don't have too... I am not trying to start an argument, just trying to relay my point of view.

First a little perspective. I'm not claiming these are 100% accurate but it is what I was able to find. These are the internal transmission ratios not the final drive ratios; final drive is determined by several factors, including transmission gearing.
https://dl.dropboxusercontent.com/u/...r%20Ratios.png
I'm sure I don't need to say it but the higher the number numerically the lower the gear ratio/final drive; this equates to faster acceleration but a much shorter useful duration for a given gear and potentially the need to shift more. With everything else being even, stock sprockets the HD 6 Speed has a closer ratio and a lower first gear than the HD 5 Speed and the Baker DD7 yeilds even closer ratios with a yet lower first gear. This is where I see increasing the final drive ratio via sprocket changes as a boon. Your transmission would stay a 1:1 at top gear but you'd be running lower RPM's at top speed in each gear. If you lined this up to meet your specific goals and requirements it starts to make sense... I'm not sure it's $2700 worth of sense but it does serve a purpose.

I will concede that I think the stock motor with no modifications isn't powerful enough - not enough torque - to adequately make use of the gear ratio as installed. Obviously there are a lot of factors to this, weight, drag and so on.

On the other hand, wake that motor up a bit and it becomes less of an issue. The more power you have - torque - the easier it becomes to launch and the faster you accelerate, which in effect shortens the gear ratio. I find myself constantly searching for a gear above 6th, I'm running a stage IV and it pulls hard all the way through.

Anpumes, you are quite right with what you say about ratios in each gear, but the internal trans ratios are only part of the equation.

My 1990 Evo 5-speed has a US spec overall top gear of 3.37:1, the TC88 I had also has a 5-speed, but top gear is 3.15:1, 6% higher. Then Harley introduced the 6-speed TC96, which jumped to 2.79:1 in top/sixth, 20% higher than an Evo. These translate to 22.23mph/1,000rpm, 23.80 and 26.87 respectively.

If we assume that an Evo had optimum gearing, then the TC88 and even more so the TC96 have 'overdrive' equivalent top gears. For an early TC96 to match an Evo when rolling the throttle in top gear, it needs 20% extra torque.

I hope that makes sense!

Absolutely, I'm in 100% agreement.

It all makes perfect sense. I was trying to simplify the information regarding the transmissions as much as I could without breaking the laws of thermodynamics. All kidding aside it was my attempt at makeing a case to justifying the DD7 as the OP requested. I know things got rather side-tracked from that original post, as they often do. So I focused on a straight transmission swap and what that would do. I also tried to briefly touch on what I'd do with it in my application, which would be to increase the overall drive ratio through sprocket changes and let my tourer stretch her legs.

My conclusion was that with everything else being equal, the DD7 transmission - in theory - would allow a bike equipped with a factory six to accelerate much quicker and have an easier take off from stopped. Obviously shifting additional gears reduces the effective gains that may or may not be possible but that requires a whole different sort of math to figure out. Hence a more powerful bike could be matched to the acceleration of a factory bike by increasing overall gearing and be longer legged overall. Probably not the primary use of this... but I'm not a drag racer so really don't know. Again just how I'd put that tranny to use for my application.

I installed it at 4k mi on my '12 RK.I live in one of the outer boros of nyc and 1st and 2nd gear was too high.For hiway riding,5 was too low and 6 too high. The DD7 Cured that for me.It shifts smoother and quieter and and the ratios are just right.I also went with the attitude chain adjuster, Baker throwout bearing and a stiffer clutch spring.Add to that a Better lever,an aftermarket shfter rod,a Pingel greaseable shifter shaft and heel shift eliminator and a a Softbrake extended shift lever.Like we say in ny,it shifts like butta.