Bonneville America Forums Forums Technical Forums General Tech Progressive fork lowering

Question for those that understand the preload top out system in the forks.

I have the Progressive front springs in the bike. I originally put one Progressive top out lowering spring in the bottom damper rod for a 1" lowering (it turns out to be more than an inch) and it was too low and the kickstand drug in left corners. It also seemed to firm up the ride as well. I took it out, and the ride is great, but the front is too high (with lowered rears). So my question is:

Could I use a piece of PVC half the height of a single top out spring to get half the lowering effect and not affect the travel or ride that I have now; assuming I make a set of spacers at the top 1/2" shorter than stock? Is my logic correct?

The effect of the 1" spring was to reduce your return travel and "fool" the fork into thinking it's 1" shorter so the whole enterprise affects the fork travel that's one reason the ride seemed firmer. I strongly suspect the use of the spring in the lower end is to keep the fork from becoming rigid at extreme compression and a pvc spacer might not react the same way. Still, how often do you bottom out your front end? (I don't think I ever have in the past 30 years).
Me...I'd be tempted to give it a go and just not push the envelope until I had some ride time in to insure there wasn't some unrecoverable defect in the plan. The real bottom line is that to shortening the fork absolutely must affect the travel and that's the answer to your question.

Hey Bryan,
I've done this and have a little info to pass on.
Cutting your spacer length down by 1/2" will not lower the front end 1/2". You may have to shorten it by as much as 1" to 2" just to see any difference in ride height.
Of course, using PVC pipe makes this very easy to do.
Shortening the spacer will lighten up the front end's stiffness. Not much but some.
It's a lot easier to just raise the fork tubes in the triple trees your required amount.

Hmm, maybe I misunderstood the question. I thought that he wanted to trim the bottom end spacer and not the preload tube....

If it's the preload tube I cut Wendys with her stock springs,I cut 2" off of it , actually made a new one from conduit that was 2" shorter. That lowered the bike too much and was just at the point where there would be no preload. That did lower it 2" as well. If you only went an inch there would still be preload with stock springs,not sure about progressives. I put it back since it was too low and scraped too much. So I ended up leaveing the rear 2" low and the front at stock height. Hope this was of some help.

Thanks for the input, guys.

Roadie had it right. I'm talking about the bottom of the assembly. To lower it according to the "book", you cut the top (spacer) and install additional springs at the bottom (oddly enough called top out springs). Each is proportionate to the other. Adding one spring at the bottom was more than I wanted. I'm trying to figure out how to add basically half a top out spring.