Ducati Pete
Hi Folks, just back from a track weekend and had a small course given by a suspension guy (Stadium suspensions).
A few interesting things came out.
You bleed the forks when they are fully extended (wheel off the ground). Otherwise, when you hit a bump, on the rebound you're going to create a negative pressure or vacuum in the forks which will have the same effect as a softer spring.
Another interesting information is that on the rear shock, the "rebound damping" actually affects both rebound and compression. It affects a part that plays a role when oil flows both ways. For that reason he suggested adjusting rebound first and then use the compression adjustment if necessary to fine tune compression damping. This only applies to the rear shock. Cartridge forks like is current today are made totally different and rebound and compression adjusters have completely separate effects.
And at last, I finally got to know what the difference between high speed and low speed compression adjustments is: The low speed adjustment is what we're used to on other bikes. The high speed adjustment acts like a relief valves that opens and lets more oil flow on very hard hits to avoid "hydraulic lockup". When you play with the adjustment you change the preload on the spring that holds the relief valve closed. You change how hard a hit it takes for that relief valve to open.
The guy had all the inner parts in his hands and seemed to know his stuff. I asked him about White power gear and he said it was good stuff. He said something about a certain part beeing made out of steel instead of aluminium (like in most japonese stock shocks or forks) and not expanding as much with heat.
A few interesting things came out.
You bleed the forks when they are fully extended (wheel off the ground). Otherwise, when you hit a bump, on the rebound you're going to create a negative pressure or vacuum in the forks which will have the same effect as a softer spring.
Another interesting information is that on the rear shock, the "rebound damping" actually affects both rebound and compression. It affects a part that plays a role when oil flows both ways. For that reason he suggested adjusting rebound first and then use the compression adjustment if necessary to fine tune compression damping. This only applies to the rear shock. Cartridge forks like is current today are made totally different and rebound and compression adjusters have completely separate effects.
And at last, I finally got to know what the difference between high speed and low speed compression adjustments is: The low speed adjustment is what we're used to on other bikes. The high speed adjustment acts like a relief valves that opens and lets more oil flow on very hard hits to avoid "hydraulic lockup". When you play with the adjustment you change the preload on the spring that holds the relief valve closed. You change how hard a hit it takes for that relief valve to open.
The guy had all the inner parts in his hands and seemed to know his stuff. I asked him about White power gear and he said it was good stuff. He said something about a certain part beeing made out of steel instead of aluminium (like in most japonese stock shocks or forks) and not expanding as much with heat.