Dyna gearing
Road Warrior
Joined: May 2010
Posts: 1,382
Likes: 4
From: Kennewick, WA
My engine builder made 4 suggestions. A larger Wimmer A/C, a SE compensator, an AIM variable pressure clutch and a smaller front sprocket to gear it down.
I bought and installed the first three suggested mods, but I didn't gear it down. I figured the build gave me enough torque to pull strong with the stock gearing. Living in the open roads of the West, I see triple digit speeds a lot, I don't want to trade that for the closer gears and shifting, just to gain more rapid acceleration. I have a gear for every need already and no problem getting up to speed in a hurry.
I always geared my off-road bikes, for the next race, to handle the fastest straights that sometimes were over 5 to10 miles at a stretch in a 100 mile desert race. I gear the Harley the same way. If your maximum held speed is under 75 MPH, then gearing down makes sense and your off-the-line acceleration will improve.
I bought and installed the first three suggested mods, but I didn't gear it down. I figured the build gave me enough torque to pull strong with the stock gearing. Living in the open roads of the West, I see triple digit speeds a lot, I don't want to trade that for the closer gears and shifting, just to gain more rapid acceleration. I have a gear for every need already and no problem getting up to speed in a hurry.
I always geared my off-road bikes, for the next race, to handle the fastest straights that sometimes were over 5 to10 miles at a stretch in a 100 mile desert race. I gear the Harley the same way. If your maximum held speed is under 75 MPH, then gearing down makes sense and your off-the-line acceleration will improve.
Ultimate HDF Member
Joined: May 2008
Posts: 6,642
Likes: 48
From: Ogden, UT
My engine builder made 4 suggestions. A larger Wimmer A/C, a SE compensator, an AIM variable pressure clutch and a smaller front sprocket to gear it down.
I bought and installed the first three suggested mods, but I didn't gear it down. I figured the build gave me enough torque to pull strong with the stock gearing. Living in the open roads of the West, I see triple digit speeds a lot, I don't want to trade that for the closer gears and shifting, just to gain more rapid acceleration. I have a gear for every need already and no problem getting up to speed in a hurry.
I always geared my off-road bikes, for the next race, to handle the fastest straights that sometimes were over 5 to10 miles at a stretch in a 100 mile desert race. I gear the Harley the same way. If your maximum held speed is under 75 MPH, then gearing down makes sense and your off-the-line acceleration will improve.
I bought and installed the first three suggested mods, but I didn't gear it down. I figured the build gave me enough torque to pull strong with the stock gearing. Living in the open roads of the West, I see triple digit speeds a lot, I don't want to trade that for the closer gears and shifting, just to gain more rapid acceleration. I have a gear for every need already and no problem getting up to speed in a hurry.
I always geared my off-road bikes, for the next race, to handle the fastest straights that sometimes were over 5 to10 miles at a stretch in a 100 mile desert race. I gear the Harley the same way. If your maximum held speed is under 75 MPH, then gearing down makes sense and your off-the-line acceleration will improve.
The difference between the 32 and 30 tooth is roughly the difference between cruising in 6th gear at 70 mph and 2200 rpm with the 32 and cruising at 70 mph and 2500 rpm with the 30 tooth. Since 2500 to 2900 is the sweet spot for cruising on the TC's, that makes it just about perfect.
Not a big difference at cruising speed at all, but it does give it just the right jump off the line.
Club Member
Joined: Jun 2007
Posts: 45,429
Likes: 2,898
From: Bedford UK
Yet another way is to change the front compensator sprocket. That makes a huge difference. I just bought a 2000 FXDX in August and the pre-owner changed the front compensator sprocket from the stock 25 tooth to a 23 tooth. Talk about a drag bike! 55MHP and turning 3100 RPM in 5th. No need to down shift from 45MPH up.
The drive chain also must be changed so this is a more expensive change.
The drive chain also must be changed so this is a more expensive change.
Do TC96 Dynas suffer from the same newer compensator as Touring models? If they do then changing that is not so easy, although that is the best place to make gearing changes.
Road Master
Joined: Jan 2010
Posts: 934
Likes: 0
From: PNW, USA
Wow a 21T, the 23T I though was low, can't imagine what a 21T would top off at.
And I want to thank everyone who posted. I really appreciate your help.
Club Member
Joined: Jun 2007
Posts: 45,429
Likes: 2,898
From: Bedford UK
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Outstanding HDF Member
Joined: Jul 2010
Posts: 2,427
Likes: 2
From: Smack Dab in the Middle of Louisiana
Perfect. Is yours a 96. Do you have a tach. Is it a 6 speed.I am wondering what the revs are at 75 mph. How does it pull as compared to before. Can you update this thread with your impressions and weather you figure it's worth it.
And I want to thank everyone who posted. I really appreciate your help.
And I want to thank everyone who posted. I really appreciate your help.
Yes I have a Speed/Tach combo. You ask what RPM's I turn at 75 MPH. Well I have to shift into third gear at that speed, so it is up at around 6000 RPM or I hit the rev limiter at about 80.
I will run the bike through its paces tonight after work and see how it responds compared to before I installed the 30 tooth gear. I do know as of last night, that it most definitely goes through the gears quicker, as the wrap up through the power-band is tighter.
I will be checking the roll-off in each gear in order to determine throttle responses. (all of this will be in an area where it can be done safely)
It has the feeling of being a stump puller.
Ultimate HDF Member
Joined: May 2008
Posts: 6,642
Likes: 48
From: Ogden, UT
Yes it's a 96cu.in. motor with 6 speed. although it has SE 259E Cams (#25482-10) and SE Pro CNC Heads (#16500013A), that have been shaved and tricked out. I am running triple digits in HP and Tq.
Yes I have a Speed/Tach combo. You ask what RPM's I turn at 75 MPH. Well I have to shift into third gear at that speed, so it is up at around 6000 RPM or I hit the rev limiter at about 80.
I will run the bike through its paces tonight after work and see how it responds compared to before I installed the 30 tooth gear. I do know as of last night, that it most definitely goes through the gears quicker, as the wrap up through the power-band is tighter.
I will be checking the roll-off in each gear in order to determine throttle responses. (all of this will be in an area where it can be done safely)
It has the feeling of being a stump puller.
Yes I have a Speed/Tach combo. You ask what RPM's I turn at 75 MPH. Well I have to shift into third gear at that speed, so it is up at around 6000 RPM or I hit the rev limiter at about 80.
I will run the bike through its paces tonight after work and see how it responds compared to before I installed the 30 tooth gear. I do know as of last night, that it most definitely goes through the gears quicker, as the wrap up through the power-band is tighter.
I will be checking the roll-off in each gear in order to determine throttle responses. (all of this will be in an area where it can be done safely)
It has the feeling of being a stump puller.
Make note of your speeds and RPM's in different gears, I think that would be the most helpful.