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Front fork rebuild issues

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Just rebuilt my forks yesterday.

 

First time rebuilding forks myself.

 

Compression adjustment doesn't seem to be making much of a difference. In any setting.

 

I've had my suspension done for enduro use by a couple different companies, and even pushing on the suspension and changing the settings will usually result in a visual significant change in where they travel to.

 

Currently - From clicker settings all the way in, to all the way out, I'm getting maybe 5/8-3/4" difference.

 

Rebound seems fine. I think I got that part right.

 

Using 5wt fork oil. 306ml (the service manual I have says 306ml... though most of the forums I'm reading are saying 370ml-400ml, so that's adding to my confusion.)

 

2006 CRF450X 205lb rider.

 

What have I screwed up?!?

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Did you dis-assemble the base valve assy?

I once messed up a compression needle's tip by re-assembling everything without first backing off the adjuster to 'full soft'.

 

Were the cartridges thoroughly bled?

meaning oil slightly overfilled, rebound rod fully cycled and excess purged out. 

 

For enduro / off-roading, unless you plan on big jumps your lower oil volume (300cc) is preferable.

That's what I run in my CRF250X and sometimes think I could even go lower.

Edited by mlatour

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Did you dis-assemble the base valve assy?
 
Were the cartridges thoroughly bled,
meaning oil slightly overfilled, rebound rod fully cycled and excess purged out. 
 
For enduro / off-roading, unless you plan on big jumps you lower oil volume (300cc) is preferable.



I did take the whole rebound assembly out. And bled them and drained the excess.

The compression adjustment just doesn't seem to be doing much. I'll take a few mL out and see how they are. They sat for probably 2 weeks while I was on shift. So there shouldn't have been much for extra oil.

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On Showa TC47 forks, the 'rebound' assy. is located on the rebound rod, also referred to as the 'mid-valve'.

Edited by mlatour

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I did blow the whole rebound assembly out with compressed air. Anything there that would mess that up?

Decided to do it myself given I'm now living so far away from any decent shop. My last Fork seal rebuild done locally was nearly $300 And lasted me 12.5 hours.

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Another consideration, an issue often mentioned in the suspension sub-forum, 

 

unlike the very similar design KYB 'SSS' forks, these Showa TC47 forks often have worn/damaged ICS piston seals and lower cartridge/rod seals

which allow a lot of cavitation inside the cartridge.

Both '08 CRF250X and '07 CRF250R I service which have had regular replacements of oil, bushing and seals suffered from this.

What felt like a properly bled cartridge during re-assy and the first ride afterwards, turned to mush forks on the following rides,

upon dis-assembly, the cartridges would 'gurgle' when cycled, meaning presence of air inside.

 

I've edited my earlier post, read about how I damaged a compression needle.

Edited by mlatour

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If the base valve assemblies were dis-assembled (nut, piston, shims removed etc.)

I can imagine an assembly error that would allow a lot of bleed (oil flow without dampening)

as an example say the rebound check valve not sealing properly

that would render the compression adjuster pretty much ineffective.

Edited by mlatour
  • Like 1

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Definitely a couple things I can look at for sure. I'm thinking I didn't properly bleed the cartridge. As in cycle all the way in and out. Definitely cycled it. But not all the way. Probably too much oil now. I made sure to back the compression rebound clickers off. So hopefully that's not it.

Appreciate all the info!

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9 hours ago, jvanidour said:

Definitely a couple things I can look at for sure. I'm thinking I didn't properly bleed the cartridge. As in cycle all the way in and out. Definitely cycled it. But not all the way. Probably too much oil now. I made sure to back the compression rebound clickers off. So hopefully that's not it.

Appreciate all the info!

Too much oil wouldn't affect the clicker...it'll just blow out of the cartridge and add itself to the outside oil level.

  • Like 3

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