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Fork prob

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Just replaced seals (and whole inner chamber piston assembly on one). Now the forks do this...

fumgw0.jpg

9jdl52.jpg

My 450 looks like this...

724ugo.jpg

The 250 forks stay like that when being ridden as well. I have about 340cc of fork oil in each tube. I bought it used so I don't know what springs are in it. I do not recall it sagging like that before I replaced the seals in both and bolt assembly in the one.

Any ideas???

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I just did a full pivot works seal/bushing rebuild on my 05 and I then went with 350ML in the fork tubes (which IMO I like). To me my forks look the same on the ground and on the stand as they did after but I did not take pictures to check this.

 

From the first 2 pics it looks like the bike is on the ground and the 3rd pic the bike is on a stand so you need to look at both bikes on the ground.

 

Did you replace the oil as per the service manual in both cartridges?

 

Do the forks work correctly?

 

Anyway, what year is your bike and your sure this wasn't the same as before?

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Both bikes are on the ground. It's a 2010 crf250r. I put it together per specs off the Racetech suspension website... The forks compress when I'm on the bike and do not rebound at all...

I may have the spring comes upside down. I'll have to dismantle to see if that's the case.

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Both bikes are on the ground. It's a 2010 crf250r. I put it together per specs off the Racetech suspension website... The forks compress when I'm on the bike and do not rebound at all...

I may have the spring comes upside down. I'll have to dismantle to see if that's the case.

the what?

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sounds like the compression rod assembly is air locked. Pull that out, compress all the way in, it should decompress its self all the way back out. 

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I took wheel off. Right fork seemed weak on extending all the way. Took it apart, replaced some o rings on the bolt assembly/cartridge, bled and put it back together. Compressed the dampening rod all the way in and it rebounded all the way out. Put the it all back together and still sags about an inch. But at least it rebounds when compressed. Still not sure what else is wrong.

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Are you following the bleed procedure in the manual?  If not, what exactly was your process?  Are you putting the right amount of oil in the inner cartridge?  How are you doing it?  Just trying to determine if you are overlooking something.  Some say to work the damper rod 20 to 30 times to bleed the air, tap the side to conjure air out, then let the cartridge sit fully extended for a couple hours (even overnight) to ensure all the air gets out.  Then overfill the oil by a few ccs to ensure no air gets back in when you insert the inner piston, followed by several small pumps and a full compression to expel any extra oil.  Are you doing these things?  If so, maybe consider replacing the damper rod seals as they could have a slow leak.  These seals aren't available OEM, but you can find aftermarket.  Replacement is a little difficult, but can be done (requires careful drilling). 

 

I'm actually kind of surprised to hear you say the rods extend ALL THE WAY, because they typically stop short (up to an inch shy of full extension) after doing a full compression to bleed off the extra oil (as instructed in the manual).

Edited by mossman77

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Fork bled fine and dampening rod did extend all the way out... Gonna take left fork back off and redo it

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Maybe let the cartridges sit overnight and then be sure they still extend fully in the morning. Maybe you have a slow leak.

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Maybe the amount of sag that's there now is normal??? They rebound smoothly and don't seem to stick anywhere

Edited by 316hepster
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I assume your looking at the top of the fork guard in relation to the upper tube.

 

I have acerbis guards and have no idea if they are the same size as yours or stock etc so if you are using the top of the guards to determine sag, it might not be accurate.

 

I would pull the fork guard on both sides and measure from the bottom of the upper tube (not the dust seal) to the top of where the bottom tube meets the axle assembly.

 

For my 05 with the bike on the ground the above measurement is 11-5/8"

 

To me this would be how to measure the fork sag but I going out on a limb here and It might be in the shop manual some where

 

EDIT - I was slightly interested and from a quick search there is NO fork sag measurement. This might give you some ideas.

 

http://www.thumpertalk.com/topic/590094-how-to-set-sag-for-front-forks/

Edited by filterx

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I was going to post this earlier so it might be redundant...

 

You need to ensure the cartridge has the correct ampont of oil and functioning correctly. I struggled trying to figure this out cus I did not have the syphon. I local shop guy told me he fills to just below the bottom of the bleed hole, then gently insert the cartridge This is messy since you get excess oil out of the cartridge and I did it over the lid of a rubber maid to catch the oil. Then follow the procedure to test. When done ,the cartridge is a closed system

 

Then fill the outer tube, re-assemble and test again etc etc

 

On another note, I have after market air bleeders. When I got the forks back together and before putting back on the bike, with the top and bottom clickers fully out, I compressed the crap out them a bunch of times to make sure they working correctly and the seal's etc were not leaking. Every 10 or so full compressions I bleed out a lot of air.

 

Anyway not sure if any of this helps but it's been raining non-stop for the last few days, puddles 3 feet deep, not riding, got a head cold and bored :(

 

Here is a pic showing the measurement I post above and it also shows where the top of the fork guard is in relationship to the upper tube.

 

20151108_104913_zpsfg4kwmqv.jpg

 

 

I'd be interested to know what you figure out

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