[Ascentrek]

I really need some good, technical advice.

How do I tune for high frequency vibrations?

I've been DHing recently more than I ever have. When I get half way down my favorite trail, there's a rocky section that's relatively easy, therefore I'm going fast. The front is shaking alot! My hands are tired from all the vibration that's translating through to the handlebars. I feel like I"m riding a rigid fork!

Here's what I got: Zoch' Super T '03. I got it in October of last year, so its not too worn out yet. I haven't changed the oil (getting ready to), but that shouldn't effect high frequency vibs?

My Thoughts:
1) Lube and clean seals for stiction
2) Change spring rate
3) Adjust it? I've tried all the preload settings, no avail.
4) Is it just the fork?

I'm really looking for some good answers.

 

[Jm_]

a lot of people use "too much" rebound, because when they are traveling at a slow to medium speed is usually when they set their rebound.

at high speed though this will cause packing and make the front or rear feel "harsh".

my bike always feels "bouncy" and at first sometimes it seems like there's not enough rebound, especially on the front end. I find that i rarely if ever get "bucked" on drops or jumps, but the fork seems to come up just as fast as I can push down. I have the same kind of damper adjustment as on your super T, and I think that I may only have it set at about 35-40% of full most of the time, maybe biased towards 35% if anything. Maybe like 4 or 5 complete turns.

at high speed, this setting works real well, because when you come up on those nasty rock gardens, the fork just sucks it up without feeling harsh. I find that I really prefer it like this usually, as going "too slow" with the rebound always makes it feel like crap in this situation, even if it's just slightly too much rebound damping

you can always go to 5wt oil (and I WOULD suggest an oil change if you haven't done one in the last 5 months or so), but I find the problem not to be that the oil isn't light enough, but just that most people are running too much rebound to the point where at real slow speeds it feels "fine" but at higher speeds it's just way too much.

as far as rate and springs, you shold have the recommended sag (about 15-25% for a fork), and if not, you need different springs. Then set the oil level after you've ensured you have the proper sag. Bad sag/spring adjustment can make a fork feel crappy despite it not bottoming out, because it's stuck deep in it's travel and the damping can't do the job before it "ramps up" at the end, not to mention the extra pressure put on the seals if you run it this way. Set oil level to prevent bottoming after getting proper sag.