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· Too many Sedonuts...
1,512 Posts
Discussion Starter · #1 ·
Can enybody explain, or post a link to a good explanation (that is not the Fox website) that describes the relationship of the:

-main air chamber
-boost chamber
-bottom out adjust

I understand the rebound knob. Just trying to get my brain around how each affects each other so I can dial mine in more.

· Au'Right!
396 Posts
It's late and I'm having trouble sleeping so let's see how bad I screw this up.....
Main air: that's your "spring pre-load" for your weight.

Boost chamber: is tied into your bottom out and propedal in 06 and 07. in 08 it's indepedant. On a VPP bike you run the BC pressure fairly low because the design of the bike dictates how it pedals (and well I might add!). This air chamber dictates how the compression damping works in the shock and the bottom out. Low psi = better small bump performance but worse pedaling. Higher psi = better pedaling but worse small bump sesitivity.

Bottom out adjust: This changes the size of the boost valve chamber and allows you to fine tune the bottom out (i.e. you go off a huge drop and either bottom out the rear shock "clunk!" or you have the bottom out dialed in so instead of driving through all the travel and bottoming it out the spring rate of the shock ramps WAY up at the end of the stroke and keeps you from hitting bottom (Fox front shocks do this function very well as well.) Of course changing this chamber also affects your propedal.

Propedal: this dial is a on the fly adjust for the boost chamber duties so to speak. Say on any other bike other than the nomad I don't reccomend people air up the boost chamber for maximum pedal performance, i say go mid way and get the best effect. i.e. you turn the propedal dial on the way "off" and you have smoother D.H. performance. turn it full on and your a climbing fool. And of course have the frigging 18 clicks in between. (the 08 is a 2 click "on" "off" thank god) thisd make any sense? Where am I?
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