sprocketing
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.
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.
Last edited by 2500hdon37s; Jan 12, 2015 at 11:01 PM.
Elite HDF Member
Joined: Sep 2012
Posts: 3,791
Likes: 57
From: N Texas
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
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
Last edited by HD Pilot; Jan 13, 2015 at 09:18 AM.
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
Elite HDF Member
Joined: Sep 2012
Posts: 3,791
Likes: 57
From: N Texas
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!
Elite HDF Member
Joined: Sep 2012
Posts: 3,791
Likes: 57
From: N Texas
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!
Last edited by HD Pilot; Jan 13, 2015 at 01:02 PM.
Advanced
Joined: Mar 2013
Posts: 72
Likes: 1
From: Iowa
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.
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Road Master
Joined: Aug 2012
Posts: 854
Likes: 20
From: CT
30/70 rocks, it's how the bike should be imo.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.
Outstanding HDF Member
Joined: Dec 2012
Posts: 2,557
Likes: 235
From: Texas
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.