Fork Oil Change

[Guest ratchethack]

Thanks for the explanation, Brian. There had to be more to it than I could dream up...

[beauchemin]

...I'm guestimating that as soon as I get out there for a proper "mountain test" that fork travel will go to 100-110 mm or even more without any change to the current settings.

65752[/snapback]

 

Hey Ratchet - have you had time for your "mountain test" yet? I assume that you will have a nice selection of bumpy roads in there? (including some bumpy corners, I hope)

[Guest ratchethack]

Chris, see your inbox for a PM.

[Guest jedione68]

Chris, see your inbox for a PM.

66556[/snapback]

 

Ratchethack,

 

Had a blast at the Hansen Dam rally, great roads out there.

 

But my front end seemed spongy, all rebound. 2000 v11s. Worst on

high speed sweepers (feels like I'm on a Norton Comando,rubbery).

Had Todd E. (aka Racer X) take a look, he played with

my rear shock, nice and he put as much adjustment as he could

on my front end (forks).

 

He said that it should feel alot better (and it did), but he

said I could and or need alot more compression.

We're thinking stronger springs and or higher weight

for oil. And I'm with him on this one.

 

Whats your thoughts? I way about 180 lbs.

And do you really have to take the fork legs out

of the triples to drain the forks (upside down???)

That, of all Guzzi things, makes no sense if its true.

 

And keep up all the good post's. See ya next time.

 

Peace, rubber side down,

Jedione68

[Guest ratchethack]

Had a blast at the Hansen Dam rally, great roads out there.

Hey Jedione68 Chris, good to see you at EMF West. Sorry I missed the Hansen Dam rally.

 

But my front end seemed spongy, all rebound.  2000 v11s.  Worst on

high speed sweepers (feels like I'm on a Norton Comando,rubbery). 

Had Todd E. (aka Racer X) take a look, he played with

my rear shock, nice and he put as much adjustment as he could

on my front end (forks). 

 

He said that it should feel alot better (and it did), but he

said I could and or need alot more compression.

We're thinking stronger springs and or higher weight

for oil.  And I'm with him on this one.

 

Whats your thoughts?  I way about 180 lbs.

And do you really have to take the fork legs out

of the triples to drain the forks (upside down???)

That, of all Guzzi things, makes no sense if its true.

Well, the woods seem to be full of people who will tell you that the Marz fork is garbage, and that your only hope of escaping shame, mediocrity, and the heartbreak of psoriasis is to replace the fork with a "racing" fork, or to install high dollar "racing" cartridges. My take is that unless you have the a proper match of spring rate to load AND have them set up properly WRT preload, air gap, and damping settings, you aren't going to have much of a clue about what the stock stock Marz cartridges are capable of. I suspect that such mastery of the obvious won't deter some from replacing 'em without ever sorting 'em, but to each his own.

 

Per my previous posts on this, I also suspect that many of us (myself included) who aren't either 1. racing or 2. chasing squids with "race bikes" over the armco are either uninterested in or (more likely) incapable of pushing the Marz fork past it's capabilities on the road - at least on anything close to a regular basis. Just what does my opinion have to do with anyone else's interests? Well, I wear my rear tires all the way to the edges, and had dragged my side-stand enough to grind off serious aluminum before shortening the stand stop. Now, despite popular delusions to the contrary, IMHO this doesn't amount to anything like "credentials" for any rider, nor does it necessarily mean that I'm any kind of a candidate for bolting the latest track tackle onto a fundamentally compromised chassis that I ride only on the road. Again - 'Fessing up here, I'm a bit of an unrepentant Road Geez, aka "duffer". Maybe that'll pass for a frame of reference?

 

You weigh about the same as I do and have the exact same fork. So it'd be reasonable to conclude that the root problem that I identified is the same in your case - the stock fork springs are hopelessly undermatched to our weight range. There's only so much you can do by adding preload to the stock springs, and without a match of spring rate to load, it ain't near enough to get the most out of any forks!

 

I did a lot of research looking at what's available RE: spring rates. I also weathered some pretty strong invective against progressive springs on this forum and elsewhere. But having previously upgraded 2 damper rod forks to progressives with excellent results, I weighed all the latest data and stuck to my original objectives. When I found that Wilbers offers a progressive spring set for the Marz 40 mm USD (thanks to Dave Laing), and Todd E. at GuzziTech gave 'em a nod for a match to my stated objectives, I decided it'd be worth a bit of a "risk" to be the guinea pig and give 'em a try.

 

For starters, I believe the Wilbers are a perfect match for our weight range, as no doubt would be many kinds of straight-rate springs. They're without any question a lot stiffer than the stock "Wimpers". This is immediately obvious when compressing them to install. The strongest evidence for a perfect match of rate to load is that BOTH static and free sag settings can be set within target ranges (at the same time, o' course). It was impossible to get the stock springs even close.

 

For me, the acid test is on the road. With the Wilbers, the ride has improved tremendously, and I'm already calling my project an unqualified success, though in all honesty, I'm still sorting things and haven't fully wrung 'em out yet. I've experimented with stock and shorter spacers, tried different air gap levels, raised the fork tubes, and will be going to Spectro 125/150 fork cartridge fluid with cranked-up damping adjusters. My latest thought on spacers for these springs is that with my heavy Vanson leathers on and a full tank of gas, the stock 110 mm spacers may get me even closer to meeting my lastest target sag measurement objectives than the shorter ones (just fine-tuning, I've decided to go just a mite firmer).

 

Yep, there's no way around taking the fork tubes out to change the fork oil. Per my previous posts on this, it's a challenge to get all the old fork oil out no matter how you do it. I've taken the forks completely apart, pulled out the entire cartridge and rod assemblies, and separated the lowers from the uppers. I've also just taken out the fork tubes and repeatedly pumped out the cartridges upside down and right-side up without dismantling. It seems that no matter how you pump the cartridges in either case, some amount of oil is (or can be) left behind. It seems to vary. So I've adopted the air space method for getting the right level back in. Getting this right makes a big difference and is critical to setting up the fork.

 

The idea of going to a different viscosity fluid is also somewhat of a challenge at this point because it's clear that some degree of mixing of old and new fluid would be at work. I'm considering flushing the forks out with an extra "purging" cycle.

 

Yep, it's a bit tedious. It's a philosophy of ownership for me, but this is just the kind of thing I'd never trust anyone else to do. I want to know exactly what's been done and how it was done at all times.

 

The first time I did a fork oil change, I swore I'd drill, countersink, tap, and plug the fork lowers before going thru this again. 2 things have stopped me from doing this: 1. When you inspect the fork lowers carefully inside and out, it becomes clear that "drilling for oil" is neither straightforward, nor simple to set up on a drill press, and that doing this carries risks. The penalty for coming up "dry" would be substantial IMHO. I'm concerned about weakening the lower casting by boring through the web of the brake hanger. It also occurs to me that there may be a very good reason that Marz doesn't install drain plugs - after all, it would have been so easy: --> 2. It seems that draining oil out from the bottom might be an even more dubious method in terms of extracting all the oil, 'cause then you provide a way to do it without turning the cartridges upside down to pump them out. It evidently has to be pumped repeatedly both ways, and even this doesn't always seem to work very well. Drain plugs would then tend to encourage less than adequate oil changes and exacerbate the overfill problem.

 

BAA, TJM, and YMMV.

 

Hope this helps.

[Guest jedione68]

Hey Jedione68 Chris, good to see you at EMF West.  Sorry I missed the Hansen Dam rally.

Well, the woods seem to be full of people who will tell you that the Marz fork is garbage, and that your only hope of escaping shame, mediocrity, and the heartbreak of psoriasis is to replace the fork with a "racing" fork, or to install high dollar "racing" cartridges.  My take is that unless you have the a proper match of spring rate to load AND have them set up properly WRT preload, air gap, and damping settings, you aren't going to have much of a clue about what the stock stock Marz cartridges are capable of.  I suspect that such mastery of the obvious won't deter many from binning them before properly dialing them in, but to each his own.

 

Per my previous posts on this, I also suspect that many of us (myself included) who aren't either 1. racing or 2. chasing squids with "race bikes" over the armco are either uninterested in or (more likely) incapable of pushing the Marz fork past it's capabilities on the road - at least on anything close to a regular basis.   Just what does my opinion have to do with anyone else's interests?  Well, I wear my rear tires all the way to the edges, and had dragged my side-stand enough to grind off serious aluminum before shortening the stand stop.  Now, despite popular delusions to the contrary, IMHO this doesn't amount to anything like "credentials" for any rider, nor does it necessarily mean that I'm any kind of a candidate for bolting the latest track tackle onto a fundamentally compromised chassis that I ride only on the road.   Again - 'Fessing up here, I'm a bit of an unrepentant Road Geez, aka "duffer". Maybe that'll pass for a frame of reference?

 

You weigh about the same as I do and have the exact same fork.  So it'd be reasonable to conclude that the root problem that I identified is the same in your case - the stock fork springs are hopelessly unmatched to our weight range.  There's only so much you can do by adding preload to the stock springs, and without a match of spring rate to load, it ain't near enough to get the most out of any forks! 

 

I did a lot of research looking at what's available RE: spring rates.  I also weathered some pretty strong invective against progressive springs on this forum and elsewhere.  But having previously upgraded 2 damper rod forks to progressives with excellent results, I weighed all the latest data and stuck to my original objectives.  When I found that Wilbers offers a progressive spring set for the Marz 40 mm USD (thanks to Dave Laing), and Todd E. at GuzziTech gave 'em a nod for a match to my stated objectives, I decided it'd be worth a bit of a "risk" to be the guinea pig and give 'em a try. 

 

For starters, I believe the Wilbers are a perfect match for our weight range, as no doubt would be many kinds of straight-rate springs.  They're without any question a lot stiffer than the stock "Wimpers".  This is immediately obvious when compressing them to install.  The strongest evidence for a perfect match of rate to load is that BOTH static and free sag settings can be set within target ranges (at the same time, o' course).  It was impossible to get the stock springs even close. 

 

For me, the acid test is on the road.  With the Wilbers, the ride has improved tremendously, and I'm already calling my project an unqualified success, though in all honesty, I'm still sorting things and haven't fully wrung 'em out yet.  I've experimented with stock and shorter spacers, tried different air gap levels, raised the fork tubes, and will be going to Spectro 125/150 fork cartridge fluid with cranked-up damping adjusters.  My latest thought on spacers for these springs is that with my heavy Vanson leathers on and a full tank of gas, the stock 110 mm spacers may get me even closer to meeting my lastest target sag measurement objectives than the shorter ones (just fine-tuning, I've decided to go just a mite firmer).

 

Yep, there's no way around taking the fork tubes out to change the fork oil.   Per my previous posts on this, it's a challenge to get all the old fork oil out no matter how you do it.  I've taken the forks completely apart, pulled out the entire cartridge and rod assemblies, and separated the lowers from the uppers.  I've also just taken out the fork tubes and repeatedly pumped out the cartridges upside down and right-side up without dismantling.  It seems that no matter how you pump the cartridges in either case, some amount of oil is (or can be) left behind.  It seems to vary.  So I've adopted the air space method for getting the right level back in.  Getting this right makes a big difference and is critical to setting up the fork. 

 

The idea of going to a different viscosity fluid is also somewhat of a challenge at this point because it's clear that some degree of mixing of old and new fluid would be at work.  I'm considering flushing the forks out with an extra "purging" cycle.

 

Yep, it's a bit tedious.  It's a philosophy of ownership for me, but this is just the kind of thing I'd never trust anyone else to do.  I want to know exactly what's been done and how it was done at all times.

 

The first time I did a fork oil change, I swore I'd drill, thread, tap, and plug the fork lowers before going thru this again.  2 things have stopped me from doing this:  1.  When you inspect the fork lowers carefully inside and out, it becomes clear that "drilling for oil" is neither straightforward, nor simple to set up on a drill press, and that doing this carries risks.  The penalty for coming up "dry" would be substantial IMHO.   I'm concerned about weakening the lower casting by boring through the structural web.  It also occurs to me that there may be a very good reason that Marz doesn't install drain plugs: -->  2.  It seems that draining oil out from the bottom might be an even more dubious method in terms of extracting all the oil, 'cause then you take away the ability to turn the dampers upside down (it evidently has to be pumped repeatedly both ways, and even this doesn't always work well) to pump them out.  If this is the case, drain plugs would tend to encourage less than adequate oil changes and exacerbate the overfill problem.

 

AATJM, and YMMV.

 

Hope this helps.

66773[/snapback]

 

Ratchethack,

 

It was good to see ya at the EMF too, had a blast, I'll have to bring

some extra Grappa or Ferent Brance to help see the way of the moon better.

And we did miss ya at the Dam. I was like the first Guzzi to show up and

was getting that evil eye about were one should park. So I did the

only thing a Guzzist can do in those situtations, PARK RIGHT IN THE DAM

MIDDLE of the whole event. And of course Brap my throttle a few times,

as if I'm making sure my AMALS are properly insink. Ha ha.

 

On the forks. I with ya. I figure I'd rather spend $1500.oo over a period

of time trying different paths in correction in stead of just going for a set

$2000. forks just to make a bunch of adjustments in the end anyways.

And I'm pretty sure there in only one or two people in the "Road" world

that could actually out ride the forks.

 

Now, I'm not saying I wouldn't like them to be set up better. There's always room

for improvement and knowledge.

 

1. So, what springs did ya go with wieght wise?

 

2. You've decided to go with 125/150 cartridge fluid?

 

3. How much of an air gap?

And is measured virtically (off the bike)

or on the bike, legs extended and wieghtless?

 

I'd like to try and get this fixed prior the Nov. 28th.

Is that possible, or should I just wait until after that

ridding date to fiddle around?

 

Thank you Ratchethack, as always, your the Guzzist.

 

Peace, rubber side down,

Jedione68

[Guest ratchethack]

On the forks.  I with ya.  I figure I'd rather spend $1500.oo over a period

of time trying different paths in correction in stead of just going for a set

$2000. forks just to make a bunch of adjustments in the end anyways.

A wise approach, IMHO. [A little personal philosophy here, YMMV] This would tend to provide a hands-on education throughout the process and thereby in the long run, better results overall.

1.  So, what springs did ya go with wieght wise?

Wilbers .7 - 1.0 kg/mm, Modell 600-062-01

2.  You've decided to go with 125/150 cartridge fluid?

Yep. You can go lower viscosity than stock IMHO, because now you're matched on rate. I find that 10 wt. now provides too much compression damping on #1 setting.

3.  How much of an air gap?

     And is measured virtically (off the bike)

     or on the bike, legs extended and wieghtless?

The recommended air gap (Luftkammer) is 100mm. This seems to provide the perfect amount of travel. I got 109 mm travel by howling the front tire with the Brembo's. This provides a nice "extra margin" at the end for those little "surprises" that pop out of nowhere on the road. The air gap is measured from the top of the fork tube, tubes installed in fork with springs removed and fork fully compressed (wheel blocked up).

I'd like to try and get this fixed prior the Nov. 28th.

Is that possible, or should I just wait until after that

ridding date to fiddle around?

If you get your order in right away you should make it, but I'd check with Todd for an updated delivery.

 

EDIT: Since you might be a little time-constrained - Just changing out springs (assuming you're not sizing new spacers) is no more than a 30 minute job. The fork oil change takes a few hours or more, depending on what else you might do while you're at it. I usually time my maintenance schedule to do brake caliper cleaning, pad replacement and bleeding the calipers at the same time. 'Course, always check wheel bearings every time the wheel's off. This'd also be the best time to inspect and lube the steering head bearings, and while you've got the headlight bucket off, it's a good time to lube the speedo cable.

 

Have fun! See ya down the road.

[dlaing]

snip

On the forks.  I with ya.  I figure I'd rather spend $1500.oo over a period

of time trying different paths in correction in stead of just going for a set

$2000. forks just to make a bunch of adjustments in the end anyways.

And I'm pretty sure there in only one or two people in the "Road" world

that could actually out ride the forks.

66846[/snapback]

I went the $2000 route and I am pretty happy for it, but it was alot of money, and I think I could have gotten half way there with just a spring upgrade, and had $1800 left over for a rear shock and who knows what else.

For me the Ohlins are not about handling, so much as about comfort.

But even with the Ohlins, I feel that I may need heavier springs...

For the Marz, I really like the idea of 10w in the rebound and something like 5W in the compression side.

[docc]

When you say your weight is 180# is that in street clothes or in your full riding kit?

 

I thought I was the perfect N. Italian 160# rider til I stepped ont he scale in Aerostich, Sidis, Arai , gloves and glasses: 175#.

[Guest jedione68]

When you say your weight is 180# is that in street clothes or in your full riding kit?

 

I thought I was the perfect N. Italian 160# rider til I stepped ont he scale in Aerostich, Sidis, Arai , gloves and glasses: 175#.

67342[/snapback]

You can kind of forget about how heavy your gear is.

With that in mind, I'd be more like 190 lbs. Cause standing

in bathroom in me "Boxers" I'm 174 to 176 lbs any given day.

(And now that the whole world knows I'm a Boxer guy).

 

But your right,

I'd be more like a low 190 with the gear.

Have to do some more thinking on this one.

 

And Dlaing, those forks of yours look great and are great.

So no worries Mate.

 

Peace,

Jedione68

[Guest trispeed]

after reading this thread, I 've decided I'll go for either the Wilbers or Traxxion fork springs. Can anyone out there verify that the forks on my 2004 V11 Sport would take the same springs as the earlier models that are referenced in this post? There seems to be some disagreement as to whether the 2004 model is 40 or 43mm??

Thanks!

[Guest ratchethack]

There seems to be some disagreement as to whether the 2004 model is 40 or 43mm??

Got calipers? Take a reading on the "male" lower tubes.

[Guest trispeed]

Hi all, I've been trying to garner some feedback re: my 2004 V11 Sport, which apparently has different forks that the models listed in this thread. The owners manual say they are 43mm Marz. and I have rebound adj. on both sides/ no compression adj. The point of my post is to determine if the fork springs mentioned here would apply to my forks, as well.

Thanks!

[Guest trispeed]

Got calipers?  Take a reading on the "male" lower tubes.

67444[/snapback]

I guess this would be a good reason to go get some