Is there a better way one over the other?

 

Personally I think a new rear pulley is an easier and faster install and cheaper way to go.

Plus with keeping the front pulley a little larger it doesnt make the belt bend as sharply so it can extend belt life a little with a larger rear pulley rather than a smaller front pulley. But either way accomplishes the same end goal of a lower final drive ratio.

I believe you can fudge about 2 teeth +/- before a new belt is required.

 

1 tooth on the front pulley is almost equal to 2 teeth on the rear pulley.

If you try to change your rear pulley by more than 2 teeth (without changing the front pulley) you will need a new belt.

Most people that want to lower their gearing will change the front pulley first to a 30T. This is a 6 % gearing change that is really noticeable.

If a 30T front pulley is not enough you can now swap out your rear pulley to a 68T or a 70T for an additional 3% or 6% lowering of your gearing.

Here is my 30T thread if you think you want to go that way:

https://www.hdforums.com/forum/dyna-...y-install.html

And a quick 68T Rear Pulley Swap thread:

https://www.hdforums.com/forum/dyna-...lley-swap.html

 

i run 30/70 and have set prob 30 bikes up wiht the same... by far IMO the very best set up for a dyna... you can get a trike 30T front pulley for about 1/2 what you can buy it from aftermarket as well, save you about $65 doing this

 

Hey Joe, you have probably told us before but how exactly to you torque that da__ pulley nut down on the new 30T? Not looking for SM instructions but how you hold that pulley when torquing with I imagine an impact wrench?

 

i use either a locking tool, or i leave the belt on and tight, then have someone apply the rear brake... that will hold the pulley in place so you can zip it off with a impact (you need a good size impact) DO NOT heat the nut, you will destroy your main seal, and have to pull your trans apart... DO NOT HEAT!!!! you will need a impact with ***** the one i use is a Ingersoll Rand and it is a BEAST!

 

Good stuff! That locking tool did not work correctly for me(or mattVA) but I did not buy an expensive one like Jims or HD, maybe those are designed differently/better and sit on the rear fork pivot nut correctly? The picture in the SM of the HD locking tool does make it look more robust and professional...

 

Not hyjacking...just wondering what gearing you would recommend with my setup. I have an 03 FXDL with 95" and Andrews gear cams. 37g. I'm not an interstate cruiser. I like acceleration and my wife will be on the back on occasion. (she has her own 883/1200 big bore). I weigh 200, she ways 155. I will start a new thread if necessary. Thanks gents.

 

30/70 rocks, it's how the bike should be imo.
Your 5spd is a little different story. It comes with much better gearing than a 6spd bike, but you can still drop it if you don't ride much highway. My buddy is running a 30t trans sprocket with 70 rear on his 95" 5spd dyna and he loves it.

 

Generally, given the same output drive rpm, increasing the size of the rear pulley (more teeth) will increase torque (acceleration) and decrease wheel rpm (speed). Decreasing the size of the rear pulley (less teeth) will decrease the torque and increase wheel rpm...the opposite is true for changes in the output drive pulley. Changes to either will affect the accuracy of your speedometer.