Fork Noise

[Mr Earl]

The forks of my 2003 M800 make a metallic ring/click noise when they rebound from compression.  I thought it was the steering head bearings, but after tearing things down today and manually compressing the forks individually, I know it's the forks.  The noise has been there for a couple of years, but seems to have gotten louder over the last few months.  It is from both forks, and always occurs after fork compression, not during.  It is consistent, and seems to emanate from inside the tubes.

I was about to change out fork oil, and possibly springs, but if new tubes are needed that would be a waste of time and money.

Does anyone know the cause of this noise, and whether I can fix it (short of tube replacement)?  Thanks.

[scott_araujo]

If you've already got them off may as well take them apart and see what's in there.  Could be as simple as a loose fastener or washer out of place.  How many miles?  Might be worn bushings.

Scott

[Jarvicious]

Looks like it's time for a cartridge upgrade 

[booger]

Might be what's called cavitation, air in the oil bath or something. If you have a non-adjustable fork I think they are prone to it. My forks(S2R) make a click on rebound that's only semi-audible, but can be felt through the handlebars. I don't know much about this. I would bet it's not your tubes though. I'm ditching the stock front end for an S2R1000 take-off as soon as I can find somebody that actually took one off. The non-adjustable forks are such a waste of time, and scary sometimes in the corners. I wish someone would come out with a fully-adjustable retrofit that didn't cost a billion dollars. 

[Mr Earl]

I forgot to note that the forks are actually working fine - I mean, as fine as they can work.  So I don't think they are worn out or have had any significant damage.  The bike has about 14K miles.  Maybe it's time to learn about the innards of fork tubes!

[Smokescreen]

+1 on cartridge inserts.  Prolly the tubes are fine, and there's just something that is at it's natural state during compression, but able to move half an inch in rebound.  The ony way to know is to take them apart, and if you are going to do that, you may as well swap out the innards for innards that don't suck, while you are at it...

[scott_araujo]

Cartridge inserts are nice but very expensive.  Taking the forks apart, cleaning, inspecting, and changing the oil is really cheap and may solve your problem.  While they may not be the best forks in the world, the right springs and oil can certainly make them a whole lot better.

I'd spend an afternoon and take them apart to have a look.  Cleaning, inspecting, and new oil shouldn't cost much at all.  New springs and oil would come out to less than $200.  New cartridges are in the $600-1000 range.  Your choice.

Scott

[Smokescreen]

gold valves run closer to $200.  While not quite as easily adjustable, once set up, they are fantastic. 

Go to racetech.com and look up your bike to see what you can get.

[scott_araujo]

This is an '03 800.  I believe that means the dreaded Marzocchis and no gold valve option.  You can drill out the dimples on the Showas and remove the shim stack/valves, not so on the Marzocchis.

Scott

[Goat_Herder]

I noticed the same thing with my 03 m620.  A little clicking sound from the fork on the rebound.  I took it to Seattle Ducati and had one of the fork/suspension specialist to check it out.  He said it sounded like a bushing going bad.  Nothing to be overly concerned with.  In my next scheduled maintenance, they will take apart the fork and replace the bushing wile they are at it. 

[Smokescreen]

My SV650 made a kind of popping noise that you could feel at rebound, so during my next oil change I slapped a Gixxer front end on there to round out the Gixxer rear I'd put on previous.  Then at my next track day the fellas at racetech were kind enough to even the bits out for me for a small fee.  No more weird sound!


Course, when she plowed into a guard rail on the crest I rather ruined the Gixxer forks.....  I'd avoid that bit.

[Mr Earl]

I thought this M800 had Showas...  this link from Ducatitech talks about the different sizes of fork cap bolts, 14mm for Showas, and 27-30mm for Marzocchis:

http://www.ducatitech.com/2v/monster_faq.html

Trouble is, the bolts on these fork caps are 19mm...

The link also says that most Monster forks are Showas, with the occasional Marzocchi thrown in.

Does anyone know a definitive way to ID Marzocchis or Showas?  I've been looking around on the 'net and can't find anything.

[Howie]

If they are Showas they will say on the inside of the fork bottom.

[scott_araujo]

I've got an '03 800 Dark and I'm pretty sure I've got Marzocchis.  Showas will have 'Showa' or an 'S' on the inside of the bottom fork leg near the axle.  You still may have Showas, they often change components mid production line.

I've heard that Modifying the Showas can be a bit of a project.  The manufacturer uses a threaded valve in the top of the cartridge but once it's fully seated they use a press to dimple into the threads, locking it in place.  To remove it you have to drill out the dimples so you can unscrew it.  If you make it that far you can get replacement valves with better and adjustable shim stacks.  Apparently the Marzocchis do the same thing but the dimple is deeper and cannot be drilled out. 

None of this is first hand knowledge, just what I found when I was trying to figure out what fork I had and what I can do with it.

Scott

[Mr Earl]

Thanks for the info, Scott.  The inside of the brake caliper mount castings at the bottom of the fork leg say MA and then a number; there's also a raised insignia on the tube part of the casting that looks like it starts with an S.  Nothing that actually says Showa or Marzocchi, though.

In any event, I'm starting to think about swapping forks.  There's been a lot of talk on this and the "other" board about what forks cross over to what year Monster.  Can anyone help me out with the information for what fits my 2003 M800 Dark (that would be an improvement)?  Preferably without triple-tree change-outs or shimming.  I'd love to have adjustable forks, but even better-grade non-adjustables would be an improvement.

Thanks.