First time service on 43 mm Marzocchi forks

[nobleswood]

I'm after some advice here. My bike's a 2004 with the Marzocchi 43 mm forks. It's, as far as I can find out, never been serviced. It doesn't leave oil rings on the lower tube, seems abit harsh on crappy roads so thought I'd change the oil and if that makes it better before twiddling with the adjusters etc.

 

Enlisted the help of a friend who has more experience with forks, as mine is zero. Now he's advising ' as we've opened them up we should change the bushes'. I can see replacing the seals, as they are cheap, but the bushes are around $80- + shipping. The full repair kit's $180. The bike's only done 8300 miles. I can't see that being necessary! Am I being too cheap? Once I've been shown how I intend to service the forks more often so I could get this done another time.

 

What's you guys advice?

[czakky]

At this point it's not the miles it's the age that will have broken down the seals on your fork. But if it's not weeping replace the oil and ride her! IMO

[docc]

+1 : not leaking? leave the seals alone.

 

Choose (lighter) oil that might reduce the harshness a wee bit .

 

Above all make sure your springs are giving you proper sag. Of the front drops more than an inch and a half, pop for correct rate springs for you weight.

 

(That's an extremely general number - lots of info and advice and opinions on fork set-up).

[Bjorn]

I Need to do this to the bike as well (03 model). Last winter I got the same idea you have, replacing the seals. Mine dont leak either. The guzzi shop did not have the seals in stock and mechanics strongly advised me not to change them if they did not leak.

 

So im with Docc on that one.

 

Shoot some pics if you can! Never found pictures of the inside of the forks of post 2003 models.

[JBBenson]

Change the springs and re-valve. I had Todd @ Guzzitech do mine and they are really, really nice now.

 

You won't know how bad the Marzocchis are until you upgrade them. Money well spent.

[nobleswood]

My intention initially is to clean out the forks, get the old oil and swarf from the tubes out & then start learning. To set them up for my weight and then get a sense of what the forks are like as the factory spec'ed them.

 

I've heard a number of members, and Guzziology say the springs are too soft. The funds aren't available this year but I'm thinking next year that might be on the plans.

 

While I'm calling around for parts & figuring out the old part numbers converted to Appilla numbers, the parts guy at MG Cycles said the 43 mm Marzocchi's also went on some of the Ducati Monsters. Has anyone had any luck using the ducati dealers for common parts? When Lisa at Moto International said the bushes were stocked in Italy and would take 3 - 4 weeks, I kept seeing $ signs.

[LowRyter]

If I was going the trouble to take them apart, I'd replace both the bushings and seals.  The deformed bushings will wear out the seals.  It's important to change both bushings in each fork.  Otherwise you'll have to take it apart again when the seals leak.  

 

If you don't like the ride, yes, change out the springs and valves.  Go with the Guzzi Tech.  Todd's done tons of development. 

 

Of course, if it's not leaking and you like the ride, don't fix it if it ain't broke.  (You can change the oil without taking the forks apart?)  I have 30k on my Greenie and unless the previous owner worked on it, the fork has never been touched.  I think the bike handles like it's on rails compared to my Bandit (with full Race Tech Gold Valves & Springs) and my EV(which as been serviced with new bushings and seals).

[GuzziMoto]

I'm with LowRyter and your buddy. If you are going in to the forks, replace the wear items. Seems crazy to do all that work only to find that they leak a few months later. 

As to spring rates, measure your sag. If you have correct Free sag (without you on board) and race sag (with you on board) you don't need to change the springs. If your measurements show sag to be off you can use that info to figure out whether you need more or less pre-load, more or less spring rate, or both.

 

There is a cheap way to increase the rate of a straight rate spring, cut a small amount off the end of the spring and replace with an equal amount of spacer. The reduces the length of the spring wire and thus makes the spring stiffer.

[Kiwi_Roy]

My greeney is at around 90k km, I had the forks apart but the seals don't leak so I just slapped them back together.

I don't know any better so I'm quite happy with the ride. 

[PDoz]

There is a cheap way to increase the rate of a straight rate spring, cut a small amount off the end of the spring and replace with an equal amount of spacer. The reduces the length of the spring wire and thus makes the spring stiffer.

This won't work with the stock spring - it's both progressive AND tapered ( ie the top is narrower to fit inside the lip of the spring preload adjuster.

 

My vote is use the $ on decent springs before you bother replacing the bushes . That's what I did, and it transformed the bike ( but I only had 10,000 km on the clock and had a wilburs rear shock)

[GuzziMoto]

 

There is a cheap way to increase the rate of a straight rate spring, cut a small amount off the end of the spring and replace with an equal amount of spacer. The reduces the length of the spring wire and thus makes the spring stiffer.

This won't work with the stock spring - it's both progressive AND tapered ( ie the top is narrower to fit inside the lip of the spring preload adjuster.

 

My vote is use the $ on decent springs before you bother replacing the bushes . That's what I did, and it transformed the bike ( but I only had 10,000 km on the clock and had a wilburs rear shock)

 

It would still work on progressive springs. But I don't recall the wife's V11 having progressive springs stock. Maybe later versions (hers is an early red frame) have progressive springs. But the trick works by shortening the length of the spring wire, which makes the remaining spring wire stiffer. On a progressive spring you could cut from either the softer end or the stiffer end and that would change the amount of change and how it impacts the rate curve.

[PDoz]

The 43's tapered progressive spring has the lighter wound part at the thinner ( top) tapered end. It fits into a lip in the spring preload thingy. Unfortunately, if you're aiming at a stiffer spring this is the end you'd need to remove so the modified spring wouldn't fit inside the lip. There is a thread somewhere on here on modifying the lip /fitting springs from an earlier set of forks.

http://www.v11lemans.com/forums/index.php?showtopic=12946&hl=marzocchi&do=findComment&comment=156367

 

 

I just fitted stiffer shorter wilbur springs and a spacer ( a bit of stainless tube from a milking machine)

[docc]

Guzzi with parts off a milking machine . . . now this is coming together!

[GuzziMoto]

The 43's tapered progressive spring has the lighter wound part at the thinner ( top) tapered end. It fits into a lip in the spring preload thingy. Unfortunately, if you're aiming at a stiffer spring this is the end you'd need to remove so the modified spring wouldn't fit inside the lip. There is a thread somewhere on here on modifying the lip /fitting springs from an earlier set of forks.

http://www.v11lemans.com/forums/index.php?showtopic=12946&hl=marzocchi&do=findComment&comment=156367

 

 

I just fitted stiffer shorter wilbur springs and a spacer ( a bit of stainless tube from a milking machine)

To try and explain this a little, with progressive springs one end is usually wound closer/tighter than the other. The side where the coils are closer together is not really softer or harder than the other side but if you wanted to put that sort of label on it the tighter side would be the softer side and cutting from that end (and replacing with a rigid spacer) would be stiffening up the soft end of the spring rate curve. The spring would start out stiffer and the rate would increase in stiffness sooner.

If you cut the other end of the spring off (and replace with a rigid spacer) you would be increasing the overall rate of the spring but not changing the shape of the curve and at what point the spring gets stiffer.

Or you could just run straight rate springs.

[kiwidave]

I have a 2002 with 60,000km on the clock.i need to install heavier springs in the front and service both. Rear shock needs service also. Were can I get springs from.