Fork oil recommendations?
Road Warrior
Joined: Aug 2007
Posts: 1,392
Likes: 43
From: South Australia
geez... shouldn't be black should it ?
My ride had done 12000kms when I drained it and it still "looked" like new, not saying that the oils properties hadn't broken down or anything but was still a nice red color just like ATF.
My ride had done 12000kms when I drained it and it still "looked" like new, not saying that the oils properties hadn't broken down or anything but was still a nice red color just like ATF.
Outstanding HDF Member
Joined: Aug 2009
Posts: 2,938
Likes: 4
From: NC
Correct as I just did a member's here when he converted over to duel disk. I know that I have about 1/3 or so of a bottle left out of 2 bottles. If you guys wish to make your ride stiffer than with stock forks just weld up the holes in the seat pipe and re-drill some more but smaller. This is how you did it before the invention of cartridge emulators. Heavier oil means more stiction = your forks work less efficient because they are slowed down.
If I am correct the only downside to using heavy weight oil in the shocks with a standard damper tube is the fork will be less supple on small minor defects in the road surface as opposed to say a set of cartridge emulators and light weight oil.
You guys running 20 weight and Progressive standard height springs, would you chime in here with your weight and riding styles? I believe this will cure my blues. My forks suck real bad and they are the next to do on my bike.
Am I correct in assuming the Progressive stock height springs drop in and also eliminate that huge OEM spacer tube??
Did that get rid of the rattling within the forks?
Tourer
Joined: Dec 2009
Posts: 406
Likes: 13
From: Langley, BC. Canada
The oil gets contaminated from the spring rubbing on the other parts in there.
I can't speak to other models or years, but my 01 Wide Glide doesn't have sensitive shims like a sport bike does. It just has holes for the oil to go through. Something like a model T. However, better oil and different weight oil will change how the forks work. I can't imagine how anyone could like the way they work with less than 15wt oil in them. It just makes the whole front end more stable. I am guessing that 20wt may be a little too stiff, but not having tried it, I can't say for sure. But I sure wouldn't go straight to 20wt without trying 15wt first. Also keep in mind that because these forks only use the same holes for compression and rebound, you will slow down both with heavier oil. I wanted that with mine and it worked out great.
I can't speak to other models or years, but my 01 Wide Glide doesn't have sensitive shims like a sport bike does. It just has holes for the oil to go through. Something like a model T. However, better oil and different weight oil will change how the forks work. I can't imagine how anyone could like the way they work with less than 15wt oil in them. It just makes the whole front end more stable. I am guessing that 20wt may be a little too stiff, but not having tried it, I can't say for sure. But I sure wouldn't go straight to 20wt without trying 15wt first. Also keep in mind that because these forks only use the same holes for compression and rebound, you will slow down both with heavier oil. I wanted that with mine and it worked out great.
Outstanding HDF Member
Joined: Aug 2009
Posts: 2,938
Likes: 4
From: NC
Well, I weigh 265 and although I dont burn up the road like I used to, I do still however ride the speed limits and dont prefer to slow much on interchanges and turnoffs. Currnetly with stock springs and oil I am bottoming on even the slightest corners.
I am hoping the Progressive stock height springs with 15 or 20 wt oil will tighten them enough that i can actually ride this bike like its mine.
Do the Progressive stock height springs get rid of that OEM spacer tube?
When I do these mods I am gonna also update the washer on the triple trees and repack and reset preload fall away.
I am hoping the Progressive stock height springs with 15 or 20 wt oil will tighten them enough that i can actually ride this bike like its mine.
Do the Progressive stock height springs get rid of that OEM spacer tube?
When I do these mods I am gonna also update the washer on the triple trees and repack and reset preload fall away.
Road Warrior
Joined: Sep 2005
Posts: 1,511
Likes: 1
From: Michigan
I realize the whole lighter oil provides a bit better response to ripples when used with tighter valving.
If I am correct the only downside to using heavy weight oil in the shocks with a standard damper tube is the fork will be less supple on small minor defects in the road surface as opposed to say a set of cartridge emulators and light weight oil.
You guys running 20 weight and Progressive standard height springs, would you chime in here with your weight and riding styles? I believe this will cure my blues. My forks suck real bad and they are the next to do on my bike.
Am I correct in assuming the Progressive stock height springs drop in and also eliminate that huge OEM spacer tube??
Did that get rid of the rattling within the forks?
If I am correct the only downside to using heavy weight oil in the shocks with a standard damper tube is the fork will be less supple on small minor defects in the road surface as opposed to say a set of cartridge emulators and light weight oil.
You guys running 20 weight and Progressive standard height springs, would you chime in here with your weight and riding styles? I believe this will cure my blues. My forks suck real bad and they are the next to do on my bike.
Am I correct in assuming the Progressive stock height springs drop in and also eliminate that huge OEM spacer tube??
Did that get rid of the rattling within the forks?
You will still have a spacer provided with the Progressive set, it is made from pvc pipe.
Outstanding HDF Member
Joined: Aug 2009
Posts: 2,938
Likes: 4
From: NC
I weigh 280 and ride mostly solo, ride to avoid potholes here in Michigan. 
You will still have a spacer provided with the Progressive set, it is made from pvc pipe.
So you are running 20 wt oil with progressive standard height springs? Correct?
What did you end up with as far as sag Loaded with rider?
You will still have a spacer provided with the Progressive set, it is made from pvc pipe.
So you are running 20 wt oil with progressive standard height springs? Correct?
What did you end up with as far as sag Loaded with rider?
Ultimate HDF Member
Joined: Jan 2007
Posts: 8,750
Likes: 261
From: back home in Michigan
I have a 2001 FXDWG Wide Glide with 41mm forks. I hated the soft bouncy nature of the forks and the clanging when they topped out. It was also very difficult to stop cleanly with just the front brake, due to the rebound effect of those soft forks.
I just changed my fork oil to 15w and it made a huge difference. The bouncy nature is gone, I can stop without looking like a rank beginner and the topping out is dramatically reduced. The forks give me much more confidence in corners and I wish I had done this sooner. I used Maxima Fork Fluid, but any good suspension fluid should work as well.
It is so easy to change the fluid in these forks. Just remove the 1 3/8" bolt on the top of the fork tube and then remove the oil drain screw on the back of the bottom of the fork tube and let the oil drain. Then put the screw back in and pour 12 oz of fluid in the top and put the bolt back in. You have no issues with spring pressure or anything else. A quick and easy job.
I just changed my fork oil to 15w and it made a huge difference. The bouncy nature is gone, I can stop without looking like a rank beginner and the topping out is dramatically reduced. The forks give me much more confidence in corners and I wish I had done this sooner. I used Maxima Fork Fluid, but any good suspension fluid should work as well.
It is so easy to change the fluid in these forks. Just remove the 1 3/8" bolt on the top of the fork tube and then remove the oil drain screw on the back of the bottom of the fork tube and let the oil drain. Then put the screw back in and pour 12 oz of fluid in the top and put the bolt back in. You have no issues with spring pressure or anything else. A quick and easy job.
Now I need to re tighten the head nut.....gotta figure out how to make up an indicator stand....
Outstanding HDF Member
Joined: Aug 2009
Posts: 2,938
Likes: 4
From: NC
I always set fall away on the tight side.To me its just a feel kinda deal. I want the front end to not fall away on its own until the higher end of the fall away measurement which is about 4 inches off center. My shop teacher always used to bust my ***** about setting the preload too loose he said. So I started going to the tight side of things and once I even experimented with overtightening the preload nut to see if you could even notice it when riding. The answer was yes. It was weird directly off center but not noticeable anywhere else. So I go with a 4 inch fall away. There isnt much grease in the neck from the factory so you best pack them up as well.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
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
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
The Best and Worst Harley-Davidson Moves of 2025
Verdad Gallardo
Outstanding HDF Member
Joined: Aug 2009
Posts: 2,938
Likes: 4
From: NC
No I would have the bike on a lift and remove the top clamp completely and allow lower tree to drop out of the cup and pack lower bearing and then do upper bearing in my hand. Reinstall. Reset fallaway and retorque top nut. I have heard of a few bikes that had dry bearings in the neck. Its not necessary but you seem like the preventive maintainance kinda rider.