[dang]

I have a question for someone who's familiar with the internals of the headshok cartridge:

I own two ultra 70 forks/w lockout but one has very little damping (to get acceptable damping I'd turn the lockout slightly to close the internal ports). with the cartridge out theres no fluid resistance when moving the shaft like the other. so I took it apart and there seems to be a damaged valve shim. looking at the red piston you see two slotted ports which has a thin shim over it but right at the port areas the shim seems to have sections broken( the shim isn't completing round) allowing you to see right through the ports.therefore theres nothing slowing the oil flow except the port size.

ok. today I took apart my other cartridge, with acceptable damping like my Lefty, and sure enough the shim completely encircles the piston and covers the ports.

so, the big question is how do,can you replace this shim? anyone know what to do??

I really don't need this cartridge because both forks are for winter only use but I should repair it before c-dale completely drops all parts for it, like my Leftly ELO.

any help would be appreciated.

 

[MendonCycleSmith]

Pics, preferably of the (in your opinion) broken, and non broken ones. Does the lockout work fully, without movement, on both? If yes, chances are either the oil is really tired, or there is lighter oil in one, than the other. Did the both come off the same size bike?

Worth noting here, Cannondale no longer has older parts, or any flavor. They stock whole unit, current stock repair parts only. I've tried, with limited success to get parts for older (like 3 years) Headshocks, and Leftys. MOst of whatI got was used, as no new ones are left. I am in no way impugning the Tech room folks, they bent over to help me, their bosses went through and had all the older stuff chucked. Way to go Pegasus, good thinking :thumbsup:

If I'm not going too far outside of legal parameters here, to you, and any others needing this stuff, I have come into a bunch of it, a frightening truck bed full of it. I can be a source, but it's getting rare out there guys, so heads up.

 

[dang]

thanks for reply. I'll get a picture on here. might be hard to see.

the lockout works fine on both.

like I said the cartridge with nice damping has a full shim covering the ports but the one with little damping has a shim that is not covering the ports so the oil just flows unimpeded. with this one I've had 20wt oil in it and still the damping was light. in the good one the oil flows through the ports hits the shim and forced out through 5 notches in the red piston. I'll have to get a photo on here.

well, might all be a moot point because parts are probably unavailable. if a car maker stopped making parts after 4 yrs there would be lots of unhappy people. same thing happened to my ELO lefty. and ironicly I didn't ride it regularly or through winter to save it and it still failed and had to be converted to dlr. nice.

 

[dang]

the cartridges are both the same but one is older but I no longer remember which is which. one is from a 2002 scalpel 2000 and the other is '99 f??? hardtail. both 70mm

 

[dang]

the cartridge with good damping has 10wt ;the light one 20wt.

 

[MendonCycleSmith]

Sounds like you are just using a light shimming. To gain stiffness, they would stack progressively larger outer diameter shims, thus stiffening the shim stack, and closing down the available space through which the oil can flow. You just need a few shims, it sounds like.