Honda CRF450R 2009 Service Manual page 60

TECHNICAL FEATURE
PSF2 (PNEUMATIC SPRING FORK 2)
(After '14)
PSF2 has a mechanism to acquire the repulsive and damping force without , - -- - - - - - - - - - -- - - - ,
separating the rooms for air and oil. AIR VALVE
Each foril: has an independent function.
- Right fork: to adjust rebound damping (high/low speed)
- left fork: to adjust compression damping (highllow speed)
PSF2
consists of
the following components:
Air valve: to adjust the PSF air pressure
Pistons (compresslonfrebound): control the damping of the fork.
Rebound spring : compresses when the fork is fully extended.
Balance spring : balances the resistant force (air spring) by generating
an extensive force when the fori( is in neutral-to-fully extended slate.
Fork cap:
- High speed adjuster: to adjust oil flow at high speed
- Low speed adjuster: to adjust oil flow at low speed
Check valve : to lubricate the outer tube and fork slider utilizing the
change of the volume in the inner damper when compressing the fork
The room for the air becomes less under compression stroke. The resistant
force increases as the sealed chamber decreases in volume.
The oil flow in the damper is as shown in the figures below.
Right fork (with rebound damping adjuster)
When compressed:
When eKtended:
2·6
lOW SPEED
HIGH SPEED
ADJUSTER
CHECK VALVE
CHECK VALVE
CHECK
PISTON
(COMPRE
SSION)
LOW SPEED
ADJUSTER
I SPEED
ADJUSTER
REBOUND
SPRING
,=i~~ ""'-
: AIR
: OIL
(REBOUND)
I
(REBOUND)
PISTON
(REBOUND)
+
PISTON
(COMPRESSION)
PISTON
(COMPRESSION)