Rockshock twin air - bottom pressure effect?

D4V1D

I have a good understanding of what the top/upper pressure job is. But what effect happens if the bottom pressure is low or alternatively if it's at a higher pressure?

I've misplaced the information.

rockmonkeysc

Experiment and you will understand it better than if anyone tries to explain it.

benpinnick

The negative spring is designed to create a static pressure balance. If you think of a coil spring its static when no weight is put on it. Its not trying to extend beyond its size - a 100mm spring is 100mm long when static. On the other hand an air spring is under load even when you're not on the forks. Its constantly trying to expand the forks to balance back to 1 bar. The negative spring is designed to pull on the airspring to return it to a static balance. If the negative spring didnt exist, you would have to put enough force on the forks to overcome the pressure before they would even move, killing small bump sensitivity.

Adding more negative air will pull harder on the spring, causing it to be more sensitive to loads placed on it (effectively the same as dropping pressure for the fist part of the stroke), removing negative air means that the air spring is no longer balanced, and so you need to get a certain amount of weight on the fork before it will move at all.

D4V1D

Cheers both are helpful.

coulddobetter

http://www.sram.com/service/rockshox/7 read the pdf docs , explained very well