Pretty in Pink, dunno why
Join Date: Feb 2009
Location: Redondo Beach
When brake dive occurs there are two things going on.
The KLR fork is not very fancy. All it has is some holes in the tubes for the oil to try and go through. The resistance of the oil going through those holes is what controls the speed at which the fork goes up and down, and so it controls how rapidly the brake dive occurs.
The forks' spring rate resists the compression of the fork under a load, so the stiffness of the spring controls how much brake dive occurs.
Now, I figure you used the progressively wound Progressive springs. Progressively wound springs are great in the right application because they are soft over small bumps but harden up with big hits (after the softer-wound portion gets stacked). The softer-wound section allows the forks valving to do it's job of controlling the forks' action over the small bumps.
Except the KLR don't have no steenkin' valving, only those holes for oil to flow through.
What you may have done is put a progressively wound spring in that has a lighter spring rate in the soft section than the stock springs had overall. That will make brake dive worse, of course. If the soft section of the progressive spring is about equal to the stock spring, then, of course, that spring will also do nothing to improve brake dive.
There are only three things I can think of that will help, and two have drawbacks.
Installing a thicker oil will make the spring compress more slowly and help to control the rate at which the dive occurs. The downside is that it will also control the rate at which the fork recovers from compression (rebound) and that may really deteriorate the handling over rough, fast terrain like washboard or stutter bumps. It won't control how much dive there is.
The second option would be install a rather decent valve like the RaceTech Emulator. The downside is that they require tuning and are expensive.
Adding oil makes the 'air spring' stiffer, that will have an effect on the brake dive if the air spring is softer than the progressive. You might play with some extremes on that and see what happens.
You cannot eliminate brake dive, but you can improve how much occurs and how fast it occurs.
Tom [email protected]
“Neither of the two people in the room paid any attention to the way I came in, although only one of them was dead.”
'How' are words so important they cannot be too often used.”
Sting like a butterfly.