Marzocchi 48mm CC Forks

Leo said:
i used 1 liter of oil. maybe 200cc in each inner chamber after screwed back the piston.
Click to expand...

Hi Leo.

But how can you make sure that the same amount of oil is on both inner chambers ? My understanding is that when putting back the piston the overflow will come out. How can you tell that both inner chambers have the same amount ?

Also, you are using the PFP with backed to 0, this is your own choice or maybe because you have more oil in the inner chamber thus creating more pressure ? Am I thinking strait or this does not makes sense ? I'm trying to understand this forks, my first CC
 
But how can you make sure that the same amount of oil is on both inner chambers ? My understanding is that when putting back the piston the overflow will come out. How can you tell that both inner chambers have the same amount ?

You is right. I don?t know. If I had measured the overflow... but I had made the same process in the both sides so, I believe that the amount of the oil is the same on both sides

Also, you are using the PFP with backed to 0, this is your own choice or maybe because you have more oil in the inner chamber thus creating more pressure ? Am I thinking strait or this does not makes sense ? I'm trying to understand this forks, my first CC

I'm using the CFP in 0 by personal choice (rock garden most of the time). You can't have too much oil in the inner chamber because the assembly process automatically dump the oil excess.
 
The valves are almost stock. My mechanic removed one shim from each side but I do not know what shim.

I'm using SAE 2.5W (Motul) Oil and the spring pre load is 0mm

I'm 70kg (154lb) :p
 
Leo said:
But how can you make sure that the same amount of oil is on both inner chambers ? My understanding is that when putting back the piston the overflow will come out. How can you tell that both inner chambers have the same amount ?

You is right. I don?t know. If I had measured the overflow... but I had made the same process in the both sides so, I believe that the amount of the oil is the same on both sides

Also, you are using the PFP with backed to 0, this is your own choice or maybe because you have more oil in the inner chamber thus creating more pressure ? Am I thinking strait or this does not makes sense ? I'm trying to understand this forks, my first CC

I'm using the CFP in 0 by personal choice (rock garden most of the time). You can't have too much oil in the inner chamber because the assembly process automatically dump the oil excess.
Click to expand...

Auto dump just like the showas.
Would it be right to assume it would be important to set the PFP at full out when bleeding the cart to assure that all the excess oil is removed.
 
What is contradicting is what Evan Yarnell stated in his evaluation. It actually makes no sense that there would be no fluid overflow or dump hole and would require absolute perfection in filling the cartridge. I can't imagine designing it this way. Leo's slide show actually shows this port. Seems simple as it should be. Maybe Evan had an early design cartridge? From what I have seen in a few sets of 45s, Marzocchi is no stranger to undocumented design variations. Also, it seems like the PFP preload position on installing the compression assy should not matter. The overall length will be the same, and the piston should displace the same amount of excess fluid. The only difference is that once the oring passes by the port and seals the cartridge, it would be stiffer to force down. Make sense?
 
So, the correct way to address the inner chamber oil level is to fill it up all to the top, insert the piston and let it overflow. Or is there a specific amount of oil to use that might vary with the spring used (15Nm, 20Nm and 25Nm) ?
 
I would think that its like you said, like the KYB/Showa, and like Leo did it in his presentation. I also would think that the overall length of the compression/piston assy is fixed by the tap, not the PFP spring or its preload, so it should be irrelavant. As long as you are sure the cartridge is fully extended, free of air, and has enough oil when the piston is inserted all should be good, just like doing a shock and inserting the seal head. I don't have mine yet so I have not confirmed this myself, but it seems logical to me.
 
Vindicator said:
So, the correct way to address the inner chamber oil level is to fill it up all to the top, insert the piston and let it overflow. Or is there a specific amount of oil to use that might vary with the spring used (15Nm, 20Nm and 25Nm) ?
Click to expand...

The correct way to do this is always fill the inner chamber with too much oil and let it overflow after. This procedure is important to bleed the air from the inner chamber. I never see in my hands but in manual the Marzocchi 50 is slightly different here. Is that the cause of the misunderstanding? Or is my english?
 
Leo said:
The correct way to do this is always fill the inner chamber with too much oil and let it overflow after. This procedure is important to bleed the air from the inner chamber. I never see in my hands but in manual the Marzocchi 50 is slightly different here. Is that the cause of the misunderstanding? Or is my english?
Click to expand...

Not at all, I just got the impression that the inner chamber would take a specific amount of oil. Thank you for your video and for sharing the information .
 
I decided to service my 48mm Zokes, they already have 35 hours on it so I figured good time as any to make sure all is in its right place.
Took everything apart except the inner cartridge, still figuring how to do it properly without breaking anything.
I found that the oil level in the outer chamber was around 230cc, with all the lost cc in my hands and pants :D I would say 250cc ... From the values we have been reading here , they do come up short.

In the cartridge oil was just about the same ~250cc . not sure if that's correct or not but I do know it's going to be a pain to close the cartridge due to the inner pressure, I now understand the gizmo Leo had to built with straps to make this work.

The oil I removed from the outer tubes was pretty contaminated even though the bushings don't appear to be worn, in any case I will replace them.
Funny was to find the oil inside the cartridge had quite a few foam on top, just like a beer :confused: , don't know if that's a good sign of the oil quality.

Apparently the oil seals from a 48mm KYB should fit this forks as well in the Sachs 48 but the reference of the NOC seal I removed is 48x58x9 and the KYB is 48x58x8,5... Do you guys think this will be an issue ? There will be a 0,5mm gap between the seal and the upper ring (the one between the seal and the bushing)

I'll post some pictures later on
 
Last edited:
Vindicator said:
Apparently the oil seals from a 48mm KYB should fit this forks as well in the Sachs 48 but the reference of the NOC seal I removed is 48x58x9 and the KYB is 48x58x8,5... Do you guys think this will be an issue ? There will be a 0,5mm gap between the seal and the upper ring (the one between the seal and the bushing)

I'll post some pictures later on
Click to expand...

I'm no expert on the matter but I think it should be fine. The oil seal will be driven up hard against the spacer (upper ring) and will stay there under its own tension. It should just mean you end up with a .5mm gap to the safety retainer clip and groove.
 
Vindicator said:
I now understand the gizmo Leo had to built with straps to make this work.
Click to expand...

Please be very careful to not strip the threads. I set the straps to make 90% of the force and not to make contact between the cap and the cartridge. It is important to have "That good feeling" in the screw.
 
Did you also do this for removal? Is it any tougher than a KYB closed cartridge fork?
 
GMP said:
Did you also do this for removal? Is it any tougher than a KYB closed cartridge fork?
Click to expand...

No. Removal is easy, just a little bit of vacuum inside that creates some suction + O-rings pressed against the inside that make hard to slide.

I find the the overall dismantle of the fork easier than the KYB simply because the minute you unscrew the bottom cap bolt you can remove the entire cartridge, no need to dismantle the rebound adjuster at the bottom.

I just had one small problem related to the tool I used, I had bought Motion Pro's Fork Compression Valve Removal Tool (http://www.motionpro.com/motorcycle/partno/08-0373/) but it's not a perfect fit, if it was another 1,5mm deep it would be perfect, have to come up with something like Leo's .
 
Leo said:
Please be very careful to not strip the threads. I set the straps to make 90% of the force and not to make contact between the cap and the cartridge. It is important to have "That good feeling" in the screw.
Click to expand...

Thanks, I just wish there was another way :cool:
 
Is there anyone who rebuilt your fork?
I think it is still a little too hard after about 40h.
I use 5W oil (Maxima racing), 300 ml in the outer leg.
 
You must log in or register to reply here.

Similar threads

S
Newbie GasGas owner / help with suspension tuning
2
Replies
23
Views
10K
Jakobi
Jakobi
N
Diving into the Sachs 48mm forks - wish me luck?
3 4 5
Replies
83
Views
42K
Ryan218
R
Back
Top