How To: adjust Softail rear shock preload

[ganno57]

The 2011 Manual is a little different. It states in turns out (counterclockwise) from minumum preload.

FLSTC, FLSTF, FLST
Less than 165 = 0
165 - 220 = 1
220 - 275 = 2
275 - 335 = 3
335 - 395 = 4
Greater than 395 = 5

FLSTFB, FLSTSB, FLSTN
Less than 185 = 0
185 - 235 = 1
235 - 285 = 2
285 - 340 = 3
Greater than 340 = 4

FXCWC
Less than 150 = 0
150 - 195 = 1
195 - 240 = 2
240 - 290 = 3
290 - 340 = 4
Greater than 340 = 5

[FatBill]

Petrock is the MFMAN!

signed: shock daddy

[petrock]

Originally Posted by FatBill

Petrock is the MFMAN!

signed: shock daddy

Thanks… Its based on your formula.

Sticky?

[FatBill]

Petrock....you are da man!

[swpwv]

I have an '08 Fatboy that I've been thinking of changing the preload on for when my ol' lady rides with me, and this helps alot. My question is, does changing the preload significantly affect the handling or control of the bike?

[Lordlindsey]

My GF and I are large.
I finally adjusted the shocks, about 4 turns on a 98 Fatboy.

Wow...what a difference. Ride is great now and have not noticed a change in handling.
Wish I would've done this a lot sooner.

[Everrdi]

I just did this on my 04 FB and it made a HUGE difference in ride and handling (for the better!). I'm a big guy, 300+, and was considering going to a touring bike before I made this change but now that I adjusted the preload, my Fatty is securely under my butt.
The only thing is that it did raise the ride height the better part of an 1 to an 1 1/2 but I'll make that sacrifice for the better ride.

[NUG]

Thank you for the detailed instruction. I'll give it a shot this weekend!

[quickster47]

Really do appreciate this information. Saved me from buying some Legend air shocks this weekend.

Carl

[sixparts]

Originally Posted by petrock

Softails's come from the factory with the lightest setting for the rear shocks (for <180lbs solo rider). However, they can handle well over 400lbs with no problems with a simple preload adjustment.

The service manual is a bit vague on how to set the preload. The procedure I use is fairly simple. Its based on the procedure from fatbillscustoms.com, but their website is gone now. It was fairly detained. I've made some tweaks to it for simplicity... Enjoy...

1) Jack the bike up so the rear tire is off the ground. The more clearance you have the easier it is. Don't forget to strap the bike down. You don't want it falling on you while your wrenching underneath it.
2) Loosen the jam nut all the way out. Its a 1-11/16" nut. If it doesn't want to loosen easily (which is often the case), soak it in some penetrating lube.
3) With a spanner wrench (HD p/n 94448-82B) turn the adjuster plate counter-clockwise (so the shock housing moves towards the front of the bike) until its up against the jam nut.
4) Then take a light colored paint pen, or a piece of duck tape, and mark the 6 o'clock position on the adjuster plate to use as a reference point when doing your adjustment. Don't worry if they're not in exactly the same position on both shocks. Thats normal.

Now your ready to adjust the shocks to your weight/load.

5) With the spanner wrench, turn the adjuster plate clockwise no more then 4 complete turns by counting how many times the mark from step 4 crosses the 6 o'clock position. 0 turns is the stiffest setting, and 4 turns is the softest setting.
6) While holding the adjuster plate in place with the spanner wrench, tighten the jam nut up against the adjuster plate by turning the nut clockwise.
6) Now repeat the exact same process on the other shock. The key is to adjust both shocks equally.

The general rule of thumb I use is:
4 turns for load <= 180 lbs
3 turns for 180lbs < load <= 235lbs
2 turns for 235lbs < load <= 300lbs
1 turn for 300lbs < load <= 375lbs
0 turns for 375 < load

Examples:
235lbs solo rider: 3 full turns
235lbs solo rider + 32lbs pack: 2.5 turns
235lbs rider + 150lbs passenger + 32lbs pack: 0.5 turns

I like a slightly stiffer ride when running solo (3 turns for my 235lbs fat booty), but run a softer ride when my girlies on the back (1 turn). Adjust your shock to taste by 1/4 turn increments till you get it dialed in for you and your riding style.

Note: you may be tempted to skip step 1 and not jack the bike up. Resist the urge. A stock ride height with the bike on its kick-stand, you may be able to use a crowsfoot or similar to get the jam nut loose, but you will have little to no room to use the spanner wrench. So take the time to do it right and jack the bike up. It only takes a minute (including strapping the bike down).

Enjoy...

Thanks for the info, it really helped, much more than the book. I made my own spanner wrench and finally got the ride i was looking for. if i can say one thing to anyone doing this,it would be to invest in a lift. i found one at a garage sale that needed a new jack, so my total investment was sixty dollars. best money i ever spent.

[cata5803]

Some good information.... Thanks...

[leeanders]

Reading the 2013 Fatboy Harley 'Owners' manual on shock adjustment, it states: "Spring preload IS adjusted to the total load" It goes on to say the setting may be varied for personal comfort. By that "total load" setting at the factory. I assumed that meant it was preset for the stiffest ride - not the softest setting. Can anyone clarify? Thanks.

[Magik]

Thanks for the info petrock! I may have to do some adjustments for some two-up riding.

[Lakerat]

Good info on preload adjustment, got a couple of friends who need these instructions. One of them can't even change his own battery without messing things up.

[hockeydawg12]

Very good info on the adjustment. I hadn't changed the shock adjustment on my Fat Boy in about 3 years. I couldn't get one loose to turn. After 2 hours of soaking the jam nut with PB Blaster and counter turning it alittle, I was eventually able to get it loose. Adjusted them right before a 1600 ride to NC and back. Made all the difference in the world riding two-up, fully loaded down.