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. It's based on the procedure from fatbillscustoms.com, but their website is gone now. It was fairly detailed. I've made some tweaks to it for simplicity... Enjoy...
Note: You may be tempted to skip step 1 and not jack the bike up. Resist the urge. At a stock ride height with the bike on its kick-stand, you may be able to use a crows foot 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...
The service manual is a bit vague on how to set the preload. The procedure I use is fairly simple. It's based on the procedure from fatbillscustoms.com, but their website is gone now. It was fairly detailed. I've made some tweaks to it for simplicity... Enjoy...
- 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 you're wrenching underneath it.
- 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.
- 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 it's up against the jam nut.
- Then take a light-colored paint pen, or a piece of duct 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. That's normal.
- With the spanner wrench, turn the adjuster plate clockwise no more than 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.
- 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.
- Now repeat the exact same process on the other shock. The key is to adjust both shocks equally.
- 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
- 235lbs solo rider: 3 full turns
- 235lbs solo rider + 32lbs pack: 2.5 turns
- 235lbs rider + 150lbs passenger + 32lbs pack: 0.5 turns
Note: You may be tempted to skip step 1 and not jack the bike up. Resist the urge. At a stock ride height with the bike on its kick-stand, you may be able to use a crows foot 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...