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Did I screw this up?

RimJobbed

Monkey
Apr 11, 2006
413
0
So first off my fork doesn't have a rebound adjustment. (05' Bomber) It's a new fork as of October. I jumped on for a cruise the other day, and it was so plush that all of my pedal force was being absorbed. I stopped in a little shop and borrowed a fork pump, I aired it back up, and put a little more in than usual. Both sides were like 65 or 70 psi. After I left I was manualling and the rebound had a slight clunk in it. Never felt it before. I wasn't sure what the deal was at the time, so I used my fingernail to push in the air valve and it squirted me in the face with fluid. I thought that there wasn't supposed to be any fluid in the air resovoir. WTF? I came to the conclusion that the rebound slack came from a loss of oil somehow, maybe back into the shop's fork pump? Did I bust a seal and now I can expect to find fluid in places it shouldn't be, or did I just allow fluid out somehow and filling it back up will fix me? Any insight would be nice, before I go spend money.
 

Bicyclist

Turbo Monkey
Apr 4, 2004
10,158
1
SB
No, that's normal. It's an open bath design.

As you increase preload, reb/comp gets faster because the same amount of damping is present for more force. That's why there was topout; the rebound essentially sped up. If you want to run it stiff, put in thicker oil to achieve the same feel.
 

SnowMongoose

Chimp
Mar 1, 2007
71
0
Bellingham, WA
yeah, tiny squirt is totally normal.
if you need say, a kleenex to get all the oil off your face, then sir, you might have problems.

I remember the first time I took air out of a fork like that, took a shot to the forehead, scared the hell out of me.
 

RimJobbed

Monkey
Apr 11, 2006
413
0
all you need to do (if you are able to) is adjust for more rebound damping to compensate for the added air pressure. everything else you said is totally normal for marz forks...
I don't understand how I would adjust for more rebound damping if my fork has no rebound adjustment. Or am I missing it altogether?
 

prana.ferox

Chimp
Aug 24, 2006
31
0
Seattle, WA
I don't understand how I would adjust for more rebound damping if my fork has no rebound adjustment. Or am I missing it altogether?
Yes you are. As Bicyclist said: if you want to run higher air pressure, put thicker oil in to slow down the rebound (aka add rebound damping) and prevent topout.
 

tomyboy

Chimp
May 9, 2003
51
0
Irvine
I don't understand how I would adjust for more rebound damping if my fork has no rebound adjustment. Or am I missing it altogether?
which 05 marzocchi fork do you have?

if it is a dirt jam(and maybe lower end dj), there is only internal rebound adjustment. You need to use a 12mm allen wrench on the right side. Check the marzocchi website for the manual and details.
 

RimJobbed

Monkey
Apr 11, 2006
413
0
ps- added fork pressure + thicker oil = a fork that doesn't work woth a crap. you might as well fill the fork with sand....
I'll keep that in mind.
It's an 05 Bomber. Kind of a crash replacement type deal, got it cheap for $250 brand new after I bent the steer tube on my DropOff. It gets the job done for the meantime.
 

WestCoastHucker

Turbo Monkey
according to the factory specs, there is a rebound adjuster on the fork. since it's a level III model, it's most likely inside the right side leg...


TARGET WEIGHT
(without steer tube) TBD
DAMPING SYSTEM Dual SSV System
ADJUSTABILITY PL/R
External Air Preload w/o Adapter
SPRING TYPE One side: Air
One side: Long Negative Coil springs
TRAVEL 130mm
STANCHIONS
(inner legs) Ø 32mm Alloy black
STEER TUBE Reinforced Alloy
DISC BRAKE MOUNT INTL STD
DROP-OUT TYPE Standard

All Mountain
 

cmc

Turbo Monkey
Nov 17, 2006
2,059
5
austin
I have the Marz Dirt Jam Pro. From day one, it rebounded out too fast, with a "kunnnnng."

The allen bolt is in the bottom of the right leg. Clearly a normal allen wrench will not reach down in there. And 12mm is really big--most people don't have one. So, I went to Auto Zone and bought a12mm allen socket with a super long socket extension.

I tried to adjust the 12mm bolt as directed in the owner's manual but it wasn't clear if it was working or not. I tried it a few different ways and it didn't seem to help the excessive-rebound problem. A few days later I drained the shock oil and replaced it with heavier weight. I can't remember if it was 10W or 15W. It definitely improved--I'm happy with the fork now. I run about 50psi, and I'm 195 lbs. I tried 70 or 80 psi for a while but I ride cross country rocky trails as well as jumps, so I like more cushion for the pushin.
 

tomyboy

Chimp
May 9, 2003
51
0
Irvine
I have the Marz Dirt Jam Pro. From day one, it rebounded out too fast, with a "kunnnnng."

The allen bolt is in the bottom of the right leg. Clearly a normal allen wrench will not reach down in there. And 12mm is really big--most people don't have one. So, I went to Auto Zone and bought a12mm allen socket with a super long socket extension.
.
If you take the spring out of the left side, you can just compress the fork down and use the 12 mm allen on the right side. The manual says it is counter clock wise to slow down the rebound.