My final drive stock is 7.78533, with just the 30 tooth tranny pulley it would jump to 8.30435, while with just the 70 tooth rear pulley it would be 8.25717, but if I had both on the bike the ratio would be 8.80764, talk about a torque monster.

 

Not sure about the spacer, and the rear pulley is same width as the OEM,
1"

Hey DopeMan, thanks for the link to the gearing calculator.

 

that pulley, as far as I know, is an 06 dyna fitment for 1 1/8 belt . I would be surprised to hear otherwise
But am listening with interest
I know of no 1 inch 70T rear (as of yet)

 

You make it sound soooo irresistible

 

Someone tell me what happens on a stock Road King Classic when all you do is increase the number of teeth on the final drive sprocket. I've wondered about this for some time now. MY stock '07 King Classic seems to me needs a few lower RPM at 70 MPH. Of course I'm not that familiar with Harley's 96 engine power band. Is changing the final drive sprocket not advisable on a stock bike?

 

If you increase the rear pulley size(as in more teeth) you will be doing more rpm at 70 mph
The 96 power band is very broad........ it makes too little power everywhere in the rev range
if you decrease the front pulley(as in less teeth) you have the same effect
If you spend most riding highway cruising, you may well want to get a larger front pulley, or smaller rear, to lower eng rpm at your preferred speed
Just make sure regarding the Drive Belt compatibility with whatever change is being considered
You will, of course, not have as much acceleration with higher gearing
Fuel economy may even get worse(or it may not, depends on your riding dynamic), as it is load that determines usage, and rpm is only one factor in that equation

 

If you put a smaller rear sprocket on, or a larger front, you are really going to hurt the power. If you are loaded, in hot weather, starting from stop signs, passing, or in hills, you're really going to notice the lack of power. If that's something you can live with, go for it and let us know how you like it.

Now, it you've got a 117" or bigger in there, then you'll probably get away with it just fine. But if it were me, I'd either leave it stock or bump the gearing up to give it more pull, not less. I want it to go when I twist the gas, not just set there making noise.




Mike

 

Hey Centerline, was just wondering if you had an update on your gearing change. How is the 30/70 doing?

 

Bump...

 

...Bobby Woods told me to do the 30/70 on my '09 RKC before I did anything else with regard to going from 96" to 103", head/cam choices, etc, but has anyone actually gotten the 30/70 combo to work with their cush drive (IDS) on an '09 or later?

If I could get this gearing combo to work with the right belt and then do the motor upgrade...

John