I bought a used 04 Dyna lowrider and it had chrome fork tubes on it already. It seems to hit fairly hard on larger bumps, so I was all ready to install Progressive fork springs in it. Upon disassembly it appears to already have progressives in it as the wider coils on one end and tighter coils on the other end. So I put it back together.
My question is did harley put the dual coil springs like progressives in from the factory or did someone already change mine to progressives? If so I guess there isn't alot I can do to help huh?

 

You can go to a heavier oil in the forks and leave the springs as is which should do the trick. The factory oil is a 5wt and a 10wt would make a noted improvement.


Fork Oil - 16oz. Type E 5wt.(stock oil) Type E is for "Showa" forks.Part # 99884-80

Fork Oil - 16oz. Type B 10w. Fork Oil - Part # 99880-73

Screamin’ EagleŽ Performance Fork Oil - A heavier oil (15wt) provides extra damping in performance application. Part # 99881-87 . Works well to take the dive out of the front end on breaking.

Screamin’ EagleŽ Racing Fork Oil - Designed and blended for the severe conditions on the race track (20wt). Not intended for street use.
Part # 99909-93R

 

I may not be of much help since I am more familiar with the baggers over the Dyna's...
However the springs that are in the touring bikes are the progressively wound springs...
Just like the ones you described...So with this said you may have the H-D springs and not the progressive...
the progressive are a larger dia. wire and are shorter in OVAL...
when you slid your spring back in did it sit flush with the top of the tube or was there quite a bit sticking out of the top? If it was flush or a bit low then they were more then likely progressives...If they stuck out past the tube several inches they were H-D...
If they are Progressive you can add a spacer that sits atop the spring to add some preload...
Go down to the hardware store and get 2ea. 3/4" PVC coupling and use it as a spacer for preloading...One on each side...
If you have H-D add the heavier fluid and start with the 10 wt. and go from there...
NOTE: All Mfg's fluid are not created equally or has the same viscosity...
Another word all 10 wts are not the same...
Good luck
paul

 

Thanks, you told me what I need to know, the springs stick out of the tops. So they are stock HD's.
I mixed up some type E with the screaming eagle fluid to create a little heavier oil but I think I'll go to a total 15 or 20 wt and forget about it. Thank both of you for the response. Take Care.

 

I wouldn't go to the 20 wt myself, it is like a brick especially in a Dyna (light bike). Even the 15 wt will be stiff, if anything I would stay with the 10 or mix it with a bit of 15 but do it evenly in both sides.