Marzocchi fork mods

General spannery stuff
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turbomart
On the Road
Posts: 22
Joined: 12 years ago

Marzocchi fork mods

Post by turbomart »

I wanted to reduce fork harshness which after much research I was convinced is due to excessive high speed compression dampening. Problem is fork damper cartridge is stamped closed. I addressed this by cutting it open with a hacksaw which allowed me to access internals.
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Then I pulled compression valve apart.
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I discovered that oil holes through valve are just 3mm in diameter, Much research has lead me to believe that this was restricting high velocity oil flow and valve shims where no longer controlling dampening.
I then carefully drilled holes to 4mm diameter (biggest I could go and have it still seal).
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Valve was then reasembled with standard shim stack.
Fitted cartidge back together and welded little bit at a time cooling with wet rag in between

Reasemmbled fork with oem oil level but used 5w oil.
Results are very good. Forks are firm but no longer jarring when hitting sharp edged bumps at speeds over 80km/h. In fact this is how they should be from factory imho. Interestingly bottoming resistance appears unaffected.
Btw, I previously tried running first 5W then 2.5W trying to remedy this problem. The 2.5w did help but still not to my satisfaction ,and it made forks too soft and a tendancy to dive excessively at low speeds.
turbomart
On the Road
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Re: Marzocchi fork mods

Post by turbomart »

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Cartridge welded back together
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Raptor 013.JPG (88.39 KiB) Viewed 2987 times
Fork reasembled
TLPower
On the Road
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Re: Marzocchi fork mods

Post by TLPower »

Top job sir, my kind of engineering, cutting metal to access stuff, modding said stuff and welding it up again.

Rear shock mod just as ingenious.

I see from your work bench your are fellow exhaust modder.

I take my hat off to you.
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snapdragon
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Location: Wiltshire

Re: Marzocchi fork mods

Post by snapdragon »

Excellent :thumbsup:

I do hope you launder that sheet before you put it back on the bed
SnappY
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Spyke
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Re: Marzocchi fork mods

Post by Spyke »

Nice work, way beyond my fettling abilities. :happyhappy:

You did the research, experimentation, and thinking before getting the hacksaw out, glad your engineering has come up trumps!
Road racing's where it's at - going round in circles all day is for hamsters.
shedmonkey
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Location: Cumbria

Re: Marzocchi fork mods

Post by shedmonkey »

Cool well done and thanks for posting ,now where is the hacksaw?
Bit of a Muppet
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