I've been working on my forks for a couple weeks and here's how it went.
I wanted to try a set of roadster damper tubes to see if they would work with all the rest of the stock parts.
The mod should net me 2" more travel on the 48 forks , as the tubes are 2" longer than the 48 model tubes.
My stock forks were 31" from caps to bottoms.
The roadster tubes made them 32 7/8" long.
The roadster tubes I used are #45925-09
I used new bottom bolts with washers #45405-75A
One quart of BelRay 7wt.
A really big guy might get away with this setup.
The mod nearly worked for me , though I couldn't set my rider sag properly because the stock springs ended up at 3 13/16" preload , they were too long unless I cut them down.
Because this wouldn't be a good idea , and hard to duplicate , I purchased a set of springs.
The Progressive Springs I used are #11-1527 which are about 18.5" long and come with 3" spacers.
Being a smaller guy I thought I'd try the spacers at 2 1/4" long which would give me a preload of 13/16" (the height of the top cap).
So this is the setup I have
Roadster Damper Tubes #45945-09
Progressive Springs #11-1527
2 Harley bolt/seal combos #45405-75A
BelRay 7wt fluid
Oil level is 6.340"
Spacers 2 1/4" long
Rider weight 170lbs
This gave me a total fork travel of 5.25"
With rider sag set at 1/3 the forks show 3.5" from the caps to the triple tree.
I have now 1.75" downward travel and 3.5" upward travel.
The ride is much better and feels stuck to the road.
Small bumps don't even bother the bike anymore , and the bigger bumps aren't as scary.
If you're bigger than me , I'd try the spacers at 2.5" to 3"
I can use all but the last 1/2" of fork travel on a really big panic stop using the front brake only.
I feel the cost/performance ratio was pretty good on this , if you can use the stock springs , it would be a great deal.
Along with the 13" Electra Glide rear shocks , the ride is worlds better than it was and I don't drag the pegs as much for sure.
Mick