Front Fork Adjustment

[Mogan]

This is a totally bonehead question, but here goes...

My Wilbers are installed and working fine. The upgrade includes the front springs. I also have upgraded brake rotors, lines, etc.

The one thing I find a bit annoying is that the front end dives too much when breaking. It feels too soft in this respect.

What's the best adjustment to make to lessen the dive and stiffen the feel upon front braking?

Current settings are:

--3 for spring preload

--8 for rebound dampening

--18 for compression dampening

 

[fjrchooser]

Measuring from the full closed position I'm running 11 clicks out on compression and 7 on rebound, about 2 1/2 lines showing on the peload. I'm also running 7.5 wt. fork oil, ride 99% of the time solo and weigh 170-175 with gear.

All the above with the Wilburs shock and springs. I still get a bit more dive than I'd like, though I do have the back jacked up about an inch over the stock height when unloaded.

There's about 10,000 miles on this setup now and front end dive has become much more noticable now than when new. Still better than it was stock so I'm not complaining. This is on an '05 ABS.

If the roads in your area will allow it I'd try tightening up the compression a bit and bump up the preload. Those last few turns on mine from 3 to 2 1/2 lines made a big difference.

 

[Warchild]

What's the best adjustment to make to lessen the dive and stiffen the feel upon front braking?

Start by increasing the pre-load (in small increments) until you are satisfied with the fork dive. Then again, you want to maintain proper sag, so don't go nuts adjusting your preload. But increasing preload (down to 2 - 2.5 rings showing) will make a huge difference.

If making these preload adjustments dork up your sag settings, or you are still unhappy with the fork dive, then as fjrchooser correctly observes, bump up your compression settings *ONE* click at a time until you are satisfied.

If all this is greek to you, here is one of THE BEST articles on bike suspension adjustments that I have ever seen... read it closely, and a lot of suspension mysteries will be explained:

Motorcycle Suspension Setup

 

[Mogan]

This is just the type of guidance I was hoping for.

THANKS GUYS!!!!!!!! :good:

 

[Mogan]

Well, I studied the article Warchild referenced and spent a few hours playing. I tried numerous interations of adjustment and ended up increasing preload to 2.5 from 3 and running 8 on both rebound and compression.

Although I haven't given it the super test on the road, the handling feels "okay" and the dive is notably less severe.

Did you guys get the wrench for rebound adjustment on the Wilbers when you purchased them or is that something we have to spring for?

Thanks again!!

 

[dobias]

Mogan,

Now that you have the basic settings to your satisfaction, raise the fork oil level in 5 mm increments until you're happy with the reduced dive. I doubt you'll want to raise it more than 10 mm.

dobias <_<

 

[Mogan]

Oooo. What impact does this have?

 

[radman]

Decreases the amount of air in the fork, which is compressable, relacing it with oil, which is not. If you can imagine the fork full to the top, it would not move at all.

 

[Mogan]

If I'm following you correctly, it simply beefs up the compression and rebound characteristics of the forks giving you a whole new range of adjustments with the compression screw and rebound knob--albeit a stiffer range?

 

[dobias]

Mogan,

No it doesn't change what settings you have (unless you've changed the viscosity).

It resists "hitting bottom" with a rapidly increasing cushion as you approach bottom.

dobias <_<

 

[Mogan]

ahh... What's the best way to measure fork oil level?

 

[yamaholic]

I use this tool:

https://www.mxdeals.com/guage-level-oil-fork.html

But a turkey baster with a hose at the end also works OK. Just measure the depth from end of hose and mark the hose/baster with a permenant marker. Then suck out what oil remains of the hose.