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My rear shock (Marzocchi supermono) seems not to respond to any regulation, so I'm afraid I have to rebuild it. I bought a used unit from eBay, but how can I tell if it is in good conditions before mounting it into the frame?

A racing mechanic recommend to rebuild it in any case, because with aging the oil loose its properties and should be replaced. It sound reasonable, but it's not so easy because the unit is very old. I found a specialist that could manually rebuild any worn components, but he asked me 700€ to do it

Since I have two units, I can afford to break one of them.... so do you think it's possile to try to change oil of one of them by myself? Is it a difficult or too specialized task?
I know that for Aprilia Pegaso or AfricaTwin it can be done:
http://www.apriliaontheroad.com/downloa ... pegaso.pdf
http://www.qsl.net/iz7ath/moto/ammortizzatore/pag01.htm

Or... does anyone knows a good (and cheap) specialist in northern Italy?

Many thanks!
LC

My racing shock specialist is in Florence and he made a very good work with front fork, but he can't tell me anything about rear before he has seen one. However he's FG dealer for tuscany, I can put you in contact with him

I bought a used unit from eBay, but how can I tell if it is in good conditions before mounting it into the frame?

The only thing I could think of is to remove the spring to see if the shock buffers if you compress it fast and also if the shock expands again to its full length so the same tests one would do with car shocks.

If is has gas (nitrogen) inside you cannot rebuild it yourself without special tools. Send it here to the states and it can be rebuilt by an Ohlins shop here in NY for $100.00

Marzhocci unit have much more pressure inside compared to Paso 750 Öhlins. It need surely some guy, who have good tools to maintain chocks. I let Öhlins dealer here to rebuild my 907 Marzhocci unit (with rebuild kit from Ducati dealer) and they told, that it was easy job, but i had to send them mail, how much was that inside pressure. Sorry, but cant remember now, how much, but anyway its "somewhere" in my accurate notes in garrage.... If need to know that pressure, let me know...

Thanks to all.

I thought the Marzocchi Supermono were a oil-only unit, with no gas... are you sure it is a mixed unit?

I will not be able to repair it on my own, but it would be interesting at least to remove the spring and test the hydraulic part only... do you think it would be dangerous or too difficult?

Finally I found three services here in northern Italy that claim to be able to work on it. Costs vary from 160eur to... 700 !!

ANTI, it would be great if you manage to find that note, since I would give it to the service! :lick:

guys, don`t you have the user manual of the Paso

There it says:
"valid for US market
Important!
If it is necessary to operate inside the MARZOCCHI rear suspension, put in AZOTE at 10 bars pressure, when re-assembling. For the ÖHLINS type use AZOTE at 18 bars"

no idea why it says "for US market" as I don`t think the shocks were any different.

but it would be interesting at least to remove the spring and test the hydraulic part only... do you think it would be dangerous or too difficult?

why should it ? you don`t open the shock, just remove the 2 rings and remove the pressure adjustment part and the spring. Measure the distance between ie. the top edge of the shock to the edge of the adjuster ring (don`t know how to name that thing) so you can put it together again as it was.

My papers say, that:

"operating pressure" 8Kgs/cm2(112 psi?) for 907IE Marzhocchi "Duo 38 remoto", stroke 66mm, what was "gas charged", by Ian Falloons book.

750 Öhlins (CA 508) was, like "G" mentioned 18 Bars.

I dont know about that 906 Marzhocci unit.... In 750 manual they talk about that "late 750 Paso" & 906 Marzhocci unit: "put 10 Bar pressure, when re-assemble". I think, i remembered wrongly in earlier, that 907 Marzhocci unit would have more pressure, that Öhlins... Sorry for that... :umm:

Also from my notes:

spring diameter(measured):
907IE: 71mm
750 Paso: 77mm

Both shocks lenght: 365mm

They take here 50€ for 907 unit rebuild 2004 in Öhlins dealer with my spare part kit from Ducati dealer.

Microfilm gives 4 different codes for all those Paso series bikes rear shocks.

I understood from Ian Falloons book, that they put shorter stroke unit to 907, caused by longer swingarm compared to 750/906...