Ducati Monster Forum

Moto Board => Tech => Topic started by: jsanford on July 14, 2011, 10:40:50 PM

Title: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: jsanford on July 14, 2011, 10:40:50 PM
Found out during my forks' first (and admittedly overdue, by the calendar anyway) servicing that the damper in the left fork has a valve stuck open.  [thumbsdown] 

Ordered an (expensive) replacement damper unit but I'm curious if others have experienced this problem with the stock  Marzocchi forks.  Or perhaps, like me, they assumed a fork performance issue was characteristic of a cost-saving design and put in an aftermarket upgrades instead of considering that there may be a mechanical problem.   [bang]

And for the record, I've never pulled off a stoppie in my life.  [Dolph]
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: suzyj on July 15, 2011, 05:36:00 AM
You are aware 695 (and 696) Marzocchi's aren't like normal forks.  Mine had no compression in one leg and no rebound in the other - really quite silly.
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: the_Journeyman on July 15, 2011, 06:05:46 AM
Speed Triples have the same setup too, one side is rebound, other side is compression.

JM
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: bikepilot on July 15, 2011, 06:17:17 AM
A lot of high end forks do this - its a means of isolating the compression and rebound circuits. The newest to jump on the wagon that I know if is the ohlins setup on the new 675R.
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: battlecry on July 15, 2011, 09:05:13 AM
I upgraded my forks to AK-20s and Right is rebound, Left is compression.

OP, do you have any damping, or one-way damping on that left fork?
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: DarkStaR on July 15, 2011, 07:48:02 PM
That's just the way they are.
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: jsanford on July 15, 2011, 11:36:20 PM
Crap---really? No, I wasn't aware. Thanks for enlightening me!

I'll call up the Ducati dealer tomorrow.  They did mention there were separate part numbers for right and left.  Hopefully I can still cancel my order.

Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: jsanford on July 18, 2011, 08:10:38 AM
Quote from: battlecry on July 15, 2011, 09:05:13 AM
I upgraded my forks to AK-20s and Right is rebound, Left is compression.

OP, do you have any damping, or one-way damping on that left fork?

No damping in the left.  The right felt more "normal."

I'm not doubting the repliers--I've had enough quirks with my Monster and my Guzzi to know not to trust that the documentation covers all the details--but the parts fiches lists just one damping unit in the exploded view of the forks and says two are required. Two people I spoke to at the two local dealerships say no, both legs should have dampers.  One said that it could just be stuck.

I may call a local suspension specialist (both dealers recommended this) or Marzocchi directly.  Took the Monster out for its first twisty ride with the new Bitubo springs, and they sure make a big diferrence, broken- or WAD-left fork and all.
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: DarkStaR on July 18, 2011, 09:18:11 AM
I've taken multiple forks off of 05 monsters that are just like that.

http://www.ducatimonsterforum.org/index.php?topic=6916.0 (http://www.ducatimonsterforum.org/index.php?topic=6916.0)
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: bikepilot on July 18, 2011, 09:21:33 AM
I don't know how this specific fork is supposed to be - I've never worked on a 695, I just know that it wouldn't be unusual.  If you strip the forks it should be pretty obvious from how its built and what the shim stack looks like whether there's supposed to be damping and it shouldn't be too complicated to figure out why there isn't damping if its supposed to have some/more.
Title: Re: Failed left fork damper at 10,900 miles on M695 (Marzocchi fork)
Post by: jsanford on July 18, 2011, 08:57:32 PM
Quote from: DarkStaR on July 18, 2011, 09:18:11 AM
I've taken multiple forks off of 05 monsters that are just like that.

http://www.ducatimonsterforum.org/index.php?topic=6916.0 (http://www.ducatimonsterforum.org/index.php?topic=6916.0)

Ah!  Thanks for this thread link.