Fork off!

Scrumpy

Scrumpy

Hero member
I have just purchased some ceriani forks to fit to a series 1 Jota from Ebay. I received them today. On inspection I found that there was no up or down movement in them. One of the fork legs sat 8mm proud of the top yoke. Releasing the pinch bolts I was unable to push it down, I suspect due to possible corrosion under the headlamp shroud. I removed the wheel spindle which enabled one fork leg to move as expected, the other moves about 2mm before coming up against a positive stop.
Overall the forks appear in good condition, using a straight edge and under artificial light I can not identify any inconsitencies in the fork tubes. Both revolve in the yokes and both sliders rotate freely.
The seller has offered me my money back if not satisfied with the goods. Naturally I want to keep them after waiting for some time for a set of forks to become available. They have been sat in his garage for 3 years, I have not used any force yet or removed the top nuts to look inside. Any suggestions would be appreciated.

Scrumpy 
 
  Recon the dampers have siezed, strip them down and have a look.

  Bad karma see, chap broke a perfectly good bike.


  Keith.
 
Keith,
He described the bike as unreliable, resulting in him breaking the bike to recoup some money. He hales from West lothian so not a million miles from you. Thanks for the advice. Couldnt I just use a large hammer :D

Scrumpy
 
As my old man used to say, "If in doubt, give it a clout". Although I think he was talking about me, I seem to remember getting a clout quite often....
 
I had to fix just that recently. It turned out the 'plunger' thing attached to the damping rod was binding on the inner wall of the slider due to decades of grunge build up. Removing the thing from the fork took a lot of persuasion but no damage was done. A good clean up and all was well. These Cerianis look well made and much nicer than Marzocchis.
 
I think you are referring to the fork stanchion (leg?) not sliding out of the triple clamps.
If you belt it out as is you risk damaging the aluminium surface in the clamp. Disassemble it bit by bit and use plenty of lube and if necessary some caretul heat to loosen it up.
Remove the top clamp, then the headlight bracket. You can now see if rust is stopping it passing down through the clamp. You could also take it out the other way (upwards). If you have to, carefully force open the clamp gap with a hardwood wedge.
When you have them stripped check the stepped bronze washer that seals the holes for rebound in the valving. High mileage shows these very worn. Spin up a new one on the lathe, make sure the matching surface on the holed washer is good and you will have proper rebound damping. (Then stick in some Goldvalves for good comp damping, a set op new springs and you are in bizz).
You were lucky to score a Ceriani front end. 
 
Thanks for the advice guys. I will strip them down and rebuild. I was tempted to place the offending fork assembly between two fixed points and use a hydraulic car jack to gently apply pressure until it moved, possibly not the best of ideas. Unfortunately I have dismantled half of the man cave and it now has a tarp for a roof so I will have to wait until it is rebuilt before I can do any work.

Tippie I had not seen a set of these for sale for a long time so was very pleased to get them. 

Scrumpy
 
Scrumpy said:
Keith,
He described the bike as unreliable, resulting in him breaking the bike to recoup some money. He hales from West lothian so not a million miles from you. Thanks for the advice. Couldnt I just use a large hammer :D

Scrumpy
Click to expand...

He's about 10 miles from here - don't think I know him* but there've been rumours of a triple up that way on & off for years. One of the other local Laverdista got in touch with a bloke up that way whose Jota didn't run well & offered to help get it going nicely but was never taken up on it.

Bob

* Though it might be the uncle of an ex-girlfriend - to be honest i'd rather not find out, less than happy memories there.
 
Hi Scrumpy, I would definitely rebuild them whether they move or not. As you know the build up of gunk can be surprising and in addition it's perfectly feasible for a DPO to have assembled them incorrectly. You can also look for odd things like burrs and rough spots from manufacturing and wear.

When rebuilding forks I always start by filling them with paraffin an leaving for a while, giving a good shake occasionally (assuming all rubber bits will be replaced anyway). Paul H
 
Bob,
The guy is called Rob, now owns a HD and rebuilds MZ's as a hobby. I have been in discussion with him about the forks and we have reached an amicable settlement.


Paul,
I will definitely be stripping them down. They will be fitted on a very long term series 1 Jota project I have going. I am just slowly acquiring bits for it. The front end now means that I have a rolling chasis with a nearly complete engine plus some other parts.

Scrumpy
 
Scrumpy said:
Bob,
The guy is called Rob, now owns a HD and rebuilds MZ's as a hobby. I have been in discussion with him about the forks and we have reached an amicable settlement.
Click to expand...

oh well, not the bloke I was thinking of (or the uncle of the ex  :D)

Glad to hear you've got it sorted amicably, that's always a good thing

Wonder if he wants another MZ to rebuild?

cheers

Bob
 
sfc1000uk said:
Scrumpy said:
Bob,
The guy is called Rob, now owns a HD and rebuilds MZ's as a hobby. I have been in discussion with him about the forks and we have reached an amicable settlement.
Click to expand...

oh well, not the bloke I was thinking of (or the uncle of the ex  :D)

Glad to hear you've got it sorted amicably, that's always a good thing

Wonder if he wants another MZ to rebuild?

cheers

Bob
Click to expand...

Bob - I can always ask him.
 
CLEAN THEM OUT....... Lazy bones !  They take NO effort !  A bottle washing brush and a stiff  wire brush will clear them thier fork sliders........... Loads of HOT WATER......


    "Uncle Sowerbutts book of home remiedies" may help.... Avaiable for JUST ?49.99 AT most good Laverda forums.....
 
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