I have a 09 Fat Bob and it seems the front end is getting more soft as time goes on. It almost feels like the rotor is warped but I am thinking it is the fork oil has broke down. The bike has around 8500 miles on it and my question is for those of you that put heavier springs in it was it a hard job and what did you buy including the new fork oil. Should I put heavier springs in or just start by changing the oil. If I put new springs in it does anything else need changed while I am in there.

 

I have and no its not a hard job at all. One thing though, your idea about the fork oil being "broke down"? Thats not your problem. Hope that saves you the time of changing the oil.

 

You can try adding some preload to the springs by using a slightly longer spacer in the tubes.
Open the top of the tube and you should have a metal spacer on top of the spring, you can use PVC pipe to replace it. No need to drain the fork oil to do this.
OR, you can drain and change the oil to a heavier weight oil, go small, don't make drastic changes all at once.

 

I have the progressive HD stock length front springs but I haven't installed them yet. But it is a simple process and you don't have to change out your oil, I will check when I get home as to the service manual states when the fork oil is due for change. But the biggest safety step for the swap out is to life your front end off the ground to remove the compression of the springs, before removing the fork nut. So once you have the front end up off the ground, loosen the top tripple tree bolt to relieve pressure on the fork. I would take some heat to the fork nut to help loosen the seal and then slowly start to turn the fork nut. Keep steady down pressure while removing the nut because the spring is under compression inside the fork. My spring kit came with new pvc spacers with the springs already cut to length. So remove the stock spacer and spring and replace with the new hardware. Install is reverse of uninstall and that is it. To replace the fork oil though to go with a differant weight, you will have to completly remove the fork from the tripple trees to drain.

 

sorry to hijack but im interested in doing the same thing. i was going to change out the preload spacer but not sure how much longer of a spacer i would need to put in. im 6ft 200lbs and after adding on my batwing with stereo (30lbs) i could use some more preload. any sugestions on how much longer i should make the spacer?

 

I experimented when I changed mine, going 1/4" longer each time, it does not take much to make a noticeable difference.

 

how much would be too much before i would need to get heavier springs

 

First try Screaming Eagle Heavy fork oil & see if that helps.
I changed to it at @ 20,000 miles for the same reason.
I didn't like it, thought it was to heavy. Went back to stock oil, another 20,000 miles... much happier.

Don't be surprised to find a low oil and/or uneven oil level from the SHOWA factory.
That's what I found in mine, plus the oil looked very sheity.. but I suspect that may have been a result of to much power washing at the quarter car wash.

Oh well, live & learn.