2021 Zeb Ultimate - Rebound Damper Shaft Question

Pheasant
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Pheasant
Edited Date/Time 8/2/2022 4:29am
Can't find this info anywhere yet so ..... Does anyone know if the above component should be able to move laterally as well as up and down? During a 50 hr service, I noticed I could point the shaft to the extremes of the stanchion circumference. Basically I can move the shaft in circles. Should it only be able to move in and out? Hope that makes sense.



I'm trying to isolate some serious knocking and vibration on descents. I can feel and hear a mechanical dudung noise (sorry Smile ) when I drop the front of the bike on a hard surface. Almost feels like a spring or something is loose but I checked everything I can and all seems ok. Really appreciate any advice etc.

Cheers
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Dickscruttock 7/31/2022 8:40am
7/31/2022 8:40am
Push it further into the stanchion and the amount you can move it will reduce. Its because at full extension the damper rod has very little bushing overlap and the damper tube is chamfered.
2
TheSuspensionLabNZ 7/31/2022 2:50pm
7/31/2022 2:50pm
Yeah if the damper is fully extended the piston isn't even seated fully in the tube and you will be able to wiggle it pretty far, its normal as this is where the bleed screw/cavity is.

Take a look at the air spring sealhead at the bottom of the stanchion. Is it Red? They changed it to silver and I have a hunch it is for this issue, the red ones were a fraction shorter and had enough room to knock up and down inside the stanchion tube. You get a silver spacer in the full service kit so it will be fixed with a rebuild
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Pheasant
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Pheasant 8/1/2022 1:38am
8/1/2022 1:38am
Thanks for the replies. Was worried I had an expensive repair ahead. I'll order up the service kit.

Cheers!
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ebruner
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ebruner 8/1/2022 1:20pm
8/1/2022 1:20pm
My Zeb Ultimate had the same knock that you are describing. I bought mine at release of the fork and had one of the original air springs with the red seal head. When I rebuilt it (and added a vorsprung secus) I used a 170mm air spring with the revised silver aluminum air spring seal head and the knocking went away.

The red seal head air spring does not move around quite as much with it installed into the CSU/Stanchions, however it still is able to move diagonally more then other air springs I had experienced in the past.
1
Pheasant
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Pheasant 8/2/2022 4:29am
8/2/2022 4:29am
Thanks ebruner! Mine does indeed have the red sealhead. £1000.00 for a fork and we still have to make it better!! :D

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