Dirt Bike Repair & Maintenance Forum

I'll be the first to admit it - I SUKK at suspension work.

But it was time for the CRF150RB to get her fork oil changed.  This bike uses a cartridge fork.

I loosed the top pinch bolt.  I backed off the rebound adjustment all the way. I loosened the fork cap. I took the fork leg off. I took the cap all the way off.  I held the locknut and removed the cap, which came out along with the damping rod.  I took the spring out. I drained the oil, and pumped the fork a few times to get as much of the oil out as I could. I measured my new oil and poured half of it in the fork.  I put my hand over the tube and compressed the fork a few times to work the air out.  With the fork leg compressed, i poured oil into the tiny center damping rod tube until it came out.  I stroked that tube about a dozen times until no more bubbles came out. I added oil to get to my proper oil height (spring out, fork completely collapsed). So far so good.  I put the spring back in, put the cap back on, tightened the locknut, put the fork back in the clamps, tightened the lower bolts, tightened the cap, then tightened the top pinch bolt.  I did the same to the other leg.

Now when I compress my fork I hear a 'ssssst' sound during rebound!

I don't remeber if it made this sound before, so I took the forks apart AGAIN.  Everything was fine. Put em back on - still 'sssssst' when they rebound (like air slowly escaping from a tire valve stem).

What - if anything - did I do wrong? I just can't recall if this sound is normal, and none of my other bikes do it, but my other bikes all have SSS type forks...

Ideas fella's??  
**

Here we go again!

IDK Skip, my only advice would be to watch a youtube how-to on changing fork oil, maybe you will see something you missed in the process.  
====================

Nobody's gonna hurt anybody. We're gonna be like little Fonzies here. And what's Fonzie like? Come on what's Fonzie like?

yeah. its semi normal i believe. my litlte p.o.s. bike does it. dont know if its cause its a pos or not., but i hear other bikes doing it too. i think its the spring rubbing on the retaining wall or something. ~pat  
PEACE GUYS ITS BEEN A BLAST!!!!! ~patrick

Can u go over the "tube stroking part again please??"  

mmmmmmmmmm......pass me those cigarettes.    

haha masterlink i was laughing my ass off at that part! but honestly i've got no clue besides pretty basic stuf im useless!!  
Strangers have the best candy.

ML - you prick  
**

Here we go again!

skipkh:
ML - you prick

LMAO  

All kidding aside. It sounds like u did everything right. And the 150 isn't a twin chamber right?  

ha ha ha ha ha man this board has gotten funnier in the past month  
=====================
ridin the dirt and the pow

Skip goofing? WOAH!!!  
--------------------------------------------------------------

skipkh:
I'll be the first to admit it - I SUKK at suspension work.

But it was time for the CRF150RB to get her fork oil changed.  This bike uses a cartridge fork.

I loosed the top pinch bolt.  I backed off the rebound adjustment all the way. I loosened the fork cap. I took the fork leg off. I took the cap all the way off.  I held the locknut and removed the cap, which came out along with the damping rod.  I took the spring out. I drained the oil, and pumped the fork a few times to get as much of the oil out as I could. I measured my new oil and poured half of it in the fork.  I put my hand over the tube and compressed the fork a few times to work the air out.  With the fork leg compressed, i poured oil into the tiny center damping rod tube until it came out.  I stroked that tube about a dozen times until no more bubbles came out. I added oil to get to my proper oil height (spring out, fork completely collapsed). So far so good.  I put the spring back in, put the cap back on, tightened the locknut, put the fork back in the clamps, tightened the lower bolts, tightened the cap, then tightened the top pinch bolt.  I did the same to the other leg.

Now when I compress my fork I hear a 'ssssst' sound during rebound!

I don't remeber if it made this sound before, so I took the forks apart AGAIN.  Everything was fine. Put em back on - still 'sssssst' when they rebound (like air slowly escaping from a tire valve stem).

What - if anything - did I do wrong? I just can't recall if this sound is normal, and none of my other bikes do it, but my other bikes all have SSS type forks...

Ideas fella's??

The exact reason I send mine to Factory Connection.  I hate working on suspension the most because I don't have all the right tools and experience to match.

So, I don't have a clue what could be wrong but hope you get it figured out!  
Dave H 2006 YZ250
(2008 YZ 125 son)

LOL, Diddo Dave. Mine goes to the shop.  
--------------------
Ruff!

It's not a twin chamber.. just like I should know better and not try to do this myself  
**

Here we go again!

Suspension should make some noise.  But I can't tell you if it's normal or not unless I hear it.

It's possible the noise was always there and you are only noticing it because you are paying attention now that you have worked on it.  Try and see if any of the other bikes in your garage make the same sound.  Particularly the new 125.  

Bill H. 2000 CR250R

skipkh:
It's not a twin chamber.. just like I should know better and not try to do this myself

i don't buy that for a second.  Ur way more than capable. I've done my own fork work on both types conventional and upside downs. i've never done a twin chamber and have as of yet to touch a rear shock. i just bought a couple of beat ones on ebay and am planning on taking them apart to see what makes em tick.

skip from what u wrote i doubt u did anything wrong and what happened when u rode it?

Give this guy a call its Richard Wilson @ Cannon Racecraft. Very knowledgeable suspension builder and racer. 405-524-7223 http://www.cannonracecraft.com/

I sent my 2002 KX250 Hillclimb forks to him because i didn't know how to make light duty dirtbike forks work on a very heavy KZ1000.
I jump my bike with ease now, they work extremely well.

 

It's true! I sukk at sospension work.

ML - I can absolutely tell if a bike is carbureted wrong (and on which circuit) just by listening to it on the track.  I can tell  how good the ignition timing is by looking at the groung arm on a plug. Heck, I can rebuild a motor with my left eye closed

But suspension?  I just can't get a handle on them...

The damping is working perfectly - I test rode it and it was fine.  I'm just not familiar with this sound, and a little self-doubt is fueling the fire. It's not a bad sound, just sounds like it's drawing a breath when coming up through the rebound stroke. "ssssttt"

Thanks for Richard's number - I'll give him a ring!  
**

Here we go again!