This is an important part in the damping system of Marzocchi’s XC600 & XC700, which is not included in the original Marzocchi Service-Kits, but there are in my Complete Rebuild-Kits and in a single set in my Shop! It is marked in the red circle on the drawing.
What is it about? You probably know that most of the Marzocchi Forks from the 90’s have Oil- / Air-Suspension. The Air does the force against Compression and the Rebound is done by expanding the Air. The Oil does the damping during compression and rebound. There is no rebound Spring in this system!
Depending on the Air-Pressure, the Oil-Level, Oil-Type and the current Driving Conditions the rebound is fast and stops by top site of the stanchions hitting bottom part of the upper bushing assembly part no. 153, in detail part no. 143, this is a squad rubber ring.
Let’s view the picture : you can see the complete bushing part no. 153 bottom up and the integrated rubber ring part no. 143 marked with 2 little arrows.
Now let’s see the 2 rubber parts on the bottom of the picture, this are used ones! If you look in detail on this rubbers in the grey circle, you can see the damages (marks) from the stanchions hitting the damper rubber part no. 143.
As this part is usualy not changed during standards bike shops services I noticed in my service works it is often defect, which results in metalic noises, when the stanchion hits the bushing assembly during rebound. Also I noted, that the original ring is not that oil resistened as it should be, is damaged or completly broken (o.k., no wondering after >20 years 😉) !!
This part is a Simple Squad Ring and unfortunately I couldn’t find it in the needed details during my researches. So simply I’m doing another reproduction to build it myself in the dimensions, material, strength and numbers I want and need for my Seal-Kits. 🔧🦾🎈👍🎏