Forkin' around

[motoguzznix]

Thanks very much! I'm relieved that SOMEBODY's forks appear to be built per my manuals specs. Was it your fork strip I was following before? Further, does this mean that there are 2 different iterations of the 43mm Marz. fork, an earlier ('02) fork retaining the adjustable compression and rebound damping, and a later ('03-04) fork with externally adjustable preload, but only rebound adjustment?

Ouiji

 

Are you sure that your fork has 43 mm diameter?

I can't believe guzzi built in 2 different 43 mm Marzocchi forks. And yours in the photographs looks absolutely identic to my 40 mm fork.

[profWacko]

Thanks very much! I'm relieved that SOMEBODY's forks appear to be built per my manuals specs. Was it your fork strip I was following before? Further, does this mean that there are 2 different iterations of the 43mm Marz. fork, an earlier ('02) fork retaining the adjustable compression and rebound damping, and a later ('03-04) fork with externally adjustable preload, but only rebound adjustment?

 

Meesathinkin you're right about the two versions.

 

The forks come apart pretty much like any others I have ever worked on. Just remembere that you have to remove the cartridge retaining screw from the bottom of the fork leg before it will come out.

 

I took mine out to pump out all of the old fluid when I changed springs.

 

-Jack

[Ouiji Veck]

Ahh...back from being sick...

 

Firstly ..The fork caps just needed a bit more force.

Done deal...just waiting for the new springs.

 

So feeling frisky I decided to attack my ugly Alt. cover and have a peek inside

while the forks and fairing wuz outta the way. I had to resort to an impact driver

on those nasty philips screws. Had to use it till they were 3/4 the way out and even

snapped the head off one.!!! Which really sucks. (see why I'm timid with the BIG hammer?)

When I got inside I got a little surprise...is this normal...whats going on after dark over

there in EEtaly.....fratrenizing with the enemy?

 

Ducati?

[Guest ratchethack]

Ducati?

Yep. Question is, does this give you MORE confidence in y'er Guzzi -- or LESS??

 

Say Weej -- Do me a favor? Y'er little excursion's got me all in an uproar. I don't know if I can sleep without knowing this f'er sure: Isn't y'er fork a 40 mm, NOT a 43 mm? At this point I'm 99.9% convinced it's a 40.

[Dan M]

Yep. Question is, does this give you MORE confidence in y'er Guzzi -- or LESS??

 

Say Weej -- Do me a favor? Y'er little excursion's got me all in an uproar. I don't know if I can sleep without knowing this f'er sure: Isn't y'er fork a 40 mm, NOT a 43 mm? At this point I'm 99.9% convinced it's a 40.

 

His bike is the same as mine, forks should be 40mm. I'm wondering how much preload he'll have to add. I needed to add 22mm with the Wilbers progressive. (I'm 180lbs + gear)

 

About that 22mm jam nut location. Maybe I'm missing something here but if you alter that measurement to change preload that way, aint ya changing the rod to screw distance for the adjuster on the fork cap???

[Ouiji Veck]

Right...according to my manual they're 40x...pleasant dreams..

I don't know how I got on the 43 mentality ...musta been

during the years of shopping I did....and it stuck.

 

Duc parts give me more confidence for sure Ratch..

Wish Duc mounted that alt. cover too...

 

Dan ..Hmm... I'm 210lbs. You added nearly an inch @ 180lbs..!!

yikes.. did you get that with the jamb nut or a spacer?

Gonna be fun compressin' the spring that far..don't like losing

that much travel either.

[Greg Field]

Dan ..Hmm... I'm 210lbs. You added nearly an inch @ 180lbs..!!

yikes.. did you get that with the jamb nut or a spacer?

Gonna be fun compressin' the spring that far..don't like losing

that much travel either.

 

One has to wonder why one would need so much preload on a spring of the correct weight? Seems to indicate the spring weight is ill-matched to the rider's weight.

[Ouiji Veck]

one did wonder that.

All the pertinent info was delivered with my order.

I'm thinking/ hoping there's some instructional documentation

comes along with the springs.

All will be revealed during sag adj.

One way or the other I'm expecting a big improvement.

[Dan M]

One has to wonder why one would need so much preload on a spring of the correct weight? Seems to indicate the spring weight is ill-matched to the rider's weight.

 

My exact point at the time. Todd @ Guzzitech assured me they were right for my girth. These springs had less unladen sag then the wimpy stockers but I thought I was needing to add an excessive amount to get both sag measurements in the ball park. I ended up shrugging and moving forward thinking that since they were progressive more than usual spacer would be needed to make a change. Likewise when I bought my wilbers shock from him and everything was to be dialed in for my weight, I needed to crank up the preload 6-7 full turns to get sags where I wanted them. Don't get me wrong, this set up front & rear works great and is a tremendous improvement over the factory stuff. I just think the matching is not exact.

 

Ouij - Compressing the spring to get the jam nut started is a bit of a wrestle but not too much trouble by hand.

[Guest ratchethack]

One has to wonder why one would need so much preload on a spring of the correct weight? Seems to indicate the spring weight is ill-matched to the rider's weight.

My thoughts exactly, Greg. I weigh 180 with full leathers and needed 6 mm LESS preload than the stock spacer with the Wilbers progressives in the 40 mm USD fork. This put my laden and unladen sags in my target ranges, and with 100 mm air gap, allowed an "ideal" fork travel of 115 mm of the available 120 mm at full bump on the road. In my case, if I'd added 22 mm preload, the sags and available fork travel would be WAY out o' whack!!

 

Dan, your question about changing the "rod to screw distance for the adjuster on the fork cap" is a good one. I've got to re-think the "conventional wisdom" on this given to me by a Pro.

[Dan M]

Dan, your question about changing the "rod to screw distance for the adjuster on the fork cap" is a good one and I had to reason myself thru this one to understand how these forks work. Here's my understanding: Making adjustments here does change the "working range" of the stroke of the cartridges within the fork by raising or lowering them internally, but this has no effect on ride height or any other aspect of operation of the fork, other than preload.

 

 

Not to beat a dead horse but I was referring to the available dampening adjustment in the fork cap. If you increase or decrease the space between the top of the rod and the screw adjuster in the cap, won't you be changing the effective range of dampening adjustment???

[Guest ratchethack]

Not to beat a dead horse but I was referring to the available dampening adjustment in the fork cap. If you increase or decrease the space between the top of the rod and the screw adjuster in the cap, won't you be changing the effective range of dampening adjustment???

EEEEEEFFFTT!!!

 

Now you've got me thinkin', Dan. Best take cover. . .

 

It would seem that these forks ain't nearly as simple to de-puzzle as the Guzzi motor!!

 

I could clearly benefit from further education here!

 

Thanks for bringing this up, Dan. Really.

 

I hadn't considered this previously, and at this point it's a complete wonderment and a mystery to Y'ers Truly, but comp & rebound adjustment appears to work SOMEHOW independently from preload adjustment via the blue adjusers and caps????? If damping adjustment is not accomplished by varying the length of the center adjustment rods according to the settings in the caps, HOW THEN?? Dammit, I've sprained me brain again.

 

Might this apparent bafflement be related to the equally baffling service manual instructions to back off the comp & rebound adjustment full counter-clockwise before dismantling?? Does damper valving in the cartridges somehow "zero out" and re-set to a new center rod length after adjusting preload via the blue anodized adjusters???

 

And now that I'm thoroughly befuddled by further mechanical repercussions and permutations, it seems that CONCEPTUALLY, now that I've re-thunk it, adjusting preload via the blue anodized adjusters would HAVE TO change ride height at the same time, due to the fact that it changes the length of the cartridge rod assemblies!!!

 

Seems to me there's 2 ways to adjust preload -- 1. Cut new spacers, as I've done. 2. Use of the adjusters. This has been apparent to me for some time, but since I learned of the function of the adjusters after cutting & re-cutting spacers and getting preload where I want it, I'd considered these to be equivalent methods with equivalent effects. It appears now that this may NOT be the case after all.

 

Wot's different between the two methods would appear to be pretty significant. Evidently, using the adjusters ALSO changes ride height by the identical amount of preload change -- achieving the same ADDITIONAL function (desired or otherwise!) WRT rake and trail changes as raising or lowering the fork stanchions in the triple clamps?!?! Re-sizing spacers clearly has no such outcome on rake and trail wotsoever.

 

Of course, NONE o' this is remotely touched upon either in the Guzzi Service manual, OR the owner's manual.

 

Hopefully one of our resident Marzocchi Maestro's will step in with an explanation and all will be made clear?!!?

 

Enquiring minds. . . .(well, you know. )

[Dan M]

EEEEEEFFFTT!!!

 

Now you've got me thinkin', Dan. Best take cover. . .

 

It would seem that these forks ain't nearly as simple to de-puzzle as the Guzzi motor!!

 

I could clearly benefit from further education here!

 

Thanks for bringing this up, Dan. Really.

 

I hadn't considered this previously, and at this point it's a complete wonderment and a mystery to Y'ers Truly, but comp & rebound adjustment appears to work SOMEHOW independently from preload adjustment via the blue adjusers and caps????? If damping adjustment is not accomplished by varying the length of the center adjustment rods according to the settings in the caps, HOW THEN?? Dammit, I've sprained me brain again.

 

Might this apparent bafflement be related to the equally baffling service manual instructions to back off the comp & rebound adjustment full counter-clockwise before dismantling?? Does damper valving in the cartridges somehow "zero out" and re-set to a new center rod length after adjusting preload via the blue anodized adjusters???

 

And now that I'm thoroughly befuddled by further mechanical repercussions and permutations, it seems that CONCEPTUALLY, now that I've re-thunk it, adjusting preload via the blue anodized adjusters would HAVE TO change ride height at the same time, due to the fact that it changes the length of the cartridge rod assemblies!!!

 

Seems to me there's 2 ways to adjust preload -- 1. Cut new spacers, as I've done. 2. Use of the adjusters. This has been apparent to me for some time, but since I learned of the function of the adjusters after cutting & re-cutting spacers and getting preload where I want it, I'd considered these to be equivalent methods with equivalent effects. It appears now that this may NOT be the case after all.

 

Wot's different between the two methods would appear to be pretty significant. Evidently, using the adjusters ALSO changes ride height by the identical amount of preload change -- achieving the same ADDITIONAL function (desired or otherwise!) WRT rake and trail changes as raising or lowering the fork stanchions in the triple clamps?!?! Re-sizing spacers clearly has no such outcome on rake and trail wotsoever.

 

Of course, NONE o' this is remotely touched upon either in the Guzzi Service manual, OR the owner's manual.

 

Hopefully one of our resident Marzocchi Maestro's will step in with an explanation and all will be made clear?!!?

 

Enquiring minds. . . .(well, you know. )

 

Well now! You are making me think hard and I may smell smoke.

 

I think that repositioning the jam nut will change preload, will have an adverse effect on dampening adjustment, and will change ride height. The adjuster in the cap limits the travel of the narrow damping rod that resides inside the main (threaded) rod. The difference between clicks is quite small so changing the position of the cap in relation of the threaded rod will change the range of adjustment greatly, or negate it altogether. The next time you have yours apart, stroke the rod (not that rod!!) and hold the damper down with your finger. You can feel how much dampening is affected. Likewise with the rebound on the right leg. I'm assuming that rod acts on a valve and the more room it has to travel, the less dampening action because it allows more fluid to flow.

Cutting spacers is the only right way (from my limited observations) I have to take a break now the smoke from my ears is starting to block my vision.

[badmotogoozer]

Gonna be fun compressin' the spring that far..don't like losing

that much travel either.

 

I precompressed my springs and threw some zip ties coil-coil to keep them compressed while I assembled. Cut them off when back together again, before filling with oil. I struggled for some time before doing this - then smooth as silk.

 

Rj

[Ouiji Veck]

Well this will be fun.

I'll do a few experiments to compare the new set up on one fork

with the stock set up on the other fork....that should add to the confusion