Harsh Cer Forks.

Vince said:
All I want is the full 130mm of travel and a nice compliant ride. Seems it's not going to happen. Again these are the 38mm Marzocchi forks wheel axle in line with the fork on my Pantah, the 38mm Cerianis are now great on my 3C.

Your cheapest and easiest solution will be a rechrome and grind of the stanchions (if required) and a set of new or good used sliders.  That will at least get it back to as good as they were when new.  Try Ian Gowanloch, he has a staggering selection of Ducati parts at his place near Tumut, and his prices are fairly reasonable AFAIK.
A conversion to a Jap fork would give a better result but with a lot more hassle, and likely cost if you can't make the stuff yourself. 
 
Its got brand new stanchions, the old ones were rusty and even with the old ones it was harsh. The bike has only dome 30,000ks so I doubt its forks are warm out.
 
Vince said:
Its got brand new stanchions, the old ones were rusty and even with the old ones it was harsh. The bike has only dome 30,000ks so I doubt its forks are warm out.

Jap forks it is then.  Early GPZ1100 or early FZR400/600 - they're both good 38mm options.  The FZR ones might be almost close enough to try out with stock springs and damping on a Pantah, if that fails then just transfer the existing emulators and springs into the Yam forks (will require some engineering).  You'll need to sort out the axle/bearings/spacers situation, and sort out the caliper/disk combo via adapters or whatever.  Bit of a job really.
......
Or just flog the Pantah for serious coin, buy a few year old Monster for next to nothing and just enjoy!  :)
 
The stanchions are brand new, lucky f they have done 300ks.Maybe the lowers have been down but I don't think so. I turned up at the suspension place last year to finally do the Emulator installation and was told they were too rusty so did a mad dash to Gowanlocks and bought new ones. They were $200 each so I expect not genuine. This morning I got some Facebook message thingy from an old site member from here who is doing the same thing except he is going full cartridge to a bevel twin. Small world and good info, last night this was at rock bottom.
For the $1200 quoted just to convert to bushes and not including the other $800 I have already spent on fitting Emulators and new Strachan's I could have bought a complete Monster front end with better brakes, lighter wheel and way better suspension and adapted that.
Nothing new to me as I have done exactly that to 3 other bikes with great results. I just expected this to be a way easier fix.







 
I did notice some blistering on one of the bottom legs that face towards the wheel and isn't easy to see with it all together.There painted black, Maybe there is some casting issue internally.Last night I was thinking I might contact glue some 240 wet and dry on an old fork stunchan and attempt to see what some rubbing might produce deep down in the fork lower leg.
 
I have heard stories that replica stanchions are not as well made as originals so I get used ones re-hard chromed.
If you attach sandpaper to an old stanchion how are you going to get it past the top bush without damaging it?
 
You taking seal or bush, I didnt think there are bushes. I would take the seal out.Here is what I really don't understand here at all. The go to replacement fork for Guzzi's with that oddball sealed damping and those that wanted stiffer front ends is exactly what I have, a 38mm Marzocchi fork. I am finding it hard to believe my reduced travel harsh fork is typical of all 38mm Marzocchi forks. It must be only my fork, I find it imposable to believe there all that bad.
 
Found that the diagonally split nylon seals around the pistons had swollen and were causing a bit of friction, nipped about a mm off and the forks consequently have a much smoother action; the lowers now drop under their own weight (springs removed of course).
 
A1 Hardchrome in Silverwater will redo your old ones for $300 cash. Better than buying new ones as they put thicker chrome than repros...
 
The bush in Marzocchis is actually an integral part of the casting.
If there was no bush there would be a lot of play in the set up.
More of a locator/guide than a bush, but still a bush of sorts.
Wear that away with sandpaper (when inserting your sandpaper/stanchion combo) and you stand the chance of wrecking the slider in a new way.
 
Vince said:
I did notice some blistering on one of the bottom legs that face towards the wheel and isn't easy to see with it all together.

Maybe that fork slider suffered a ding at some stage in its life, perhaps before you owned the bike. Before you start poking abrasive stuff down the fork leg, is there some way to measure the ID of the slider tube in various positions?
Perhaps there's a restriction at a particular spot.  If your suspension guru can't work it out, then perhaps he isn't such a guru.
 
Vince said:
It would be an attempt to smooth out any resistance or casting flaws. It's just an idea at the moment.

I know what you are trying to do, but you will not get your sandpaper/stanchion past the 'bush' without damage.

If you slide a bare stanchion down each slider is there a point at which there seems to be a sticky spot?
If not then you are pissing against the wind trying to rub something away that the stanchion can't find.
 
Gravelroad said:
Hmm, never seen them with Schrader valves on the fork caps, that might be aftermarket items? You could also remove the valve inserts and put the valve caps back on loosely for a test.

Just went down to the shed to take some photos of the Morini's vented fork caps. See pictures added below.
First picture shows the vent hole at the center of the pin at the inside of the fork cap. Second picture shows the cap from the top with the countersunk slotted screw sitting inside the allen key hex. Third picture then shows the spring and the ball sitting under the screw. Looking closely at the seat of the screw, you can spot the remains of the ridges, intended to allow air passing by the screw head. The slotted countersunk screws are a actually a standard item, my memory had played tricks with me here, so forget what a said about them in my last post.
Anyone have any tips on how to get that slotted screw undone?
Reckon mine will be guncked up so the venting won't work. I put a probe into the hole underneath and was able to push the ball against the spring although intitially it felt stuck to. I'd say well worth a clean out but that screw doesn't want to budge.
 
After a long soak in your favourite penetrator, maybe one of those Impact tools you hit with a hammer. They were the tool of choice years ago for those soap like Philips case screws on Japanese bikes.
 
Vince said:
After a long soak in your favourite penetrator, maybe one of those Impact tools you hit with a hammer. They were the tool of choice years ago for those soap like Philips case screws on Japanese bikes.
Yeh, used to use mine all the time on my Honda 4 in the mid '70's............. ;) (still have the same impact driver too,........)
Just a bit dodgy about taking a hammer to the forks. Actually I have the forks out and caps off at present so have been trying to hold the cap in a vice (with suitable padding) but that aint gonna be enough for an impact driver. Guess I may have to put back together and try. Anyway will persevere and see how I go...............
 
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