"old" V11 sport frame

[dlaing]

I think Ratchet's suspension modification was under $150 in parts and little more labor than the normal fork service.

EDIT FWIW my Ohlins forks were a lot more, and they are obviously not for everyone, but spending $2000 is not what Ratchet is talking about.

The HyperCoil spring for my Sachs was $60 plus shipping (US dollars)...but installation was a pain....Traxxion and RaceTech will charge a bit over $100 for the spring, but installation is free(minus shipping).

I disagree with Ratchet's term Perfect as I don't think there is such a thing as perfect suspension setup.

But Excellent Sag numbers are easily achievable and they will make your bike ride better to a degree that is directly proportional to how far off they were.

You don't have to do it, and you don't have to put ideal air pressure in your tires, either....

[luhbo]

......

But Excellent Sag numbers are easily achievable and they will make your bike ride better to a degree that is directly proportional to how far off they were.

......

 

That's a good point! How far off are they actually, right out of the box?

 

If someone feels he had to make the front fork 50% stiffer he probably does not look like Marlon Brando in his late years. Must have the shape of a walrus, in its middle years at least.

 

Hubert

[Guest ratchethack]

. . . How far off are they actually, right out of the box?

Since the correct springs are a match of rate to load, how far off they are depends both on your riding weight and preload.

If someone feels he had to make the front fork 50% stiffer he probably does not look like Marlon Brando in his late years. Must have the shape of a walrus, in its middle years at least.

Hubert, please. Let's not be silly. I thought the following had been covered adequately, ad nauseum, by Yours Truly as recently as posts #16 and #44 in this thread, but evidently it bears repeating:

 

The stock springs that arrive from Mandello in the 40 mm USD Marz forks are rated at about .6 kg/mm. While I have no good way to precisely measure them, I have compared them as carefully as possible against springs of known rate by compressing them both on a scale on a bench, side by side.

 

The stock .6 kg/mm fork springs will only ALLOW laden and unladen sag settings in the correct range if the riding weight is about 135 lbs., or a little over 61 kg.

 

Many Forum members are riding on fork springs of nearly DOUBLE the stock Marz spring rate. A commonly available replacement fork spring rate for heavier riders is 1.1 kg/mm. That's nearly a 100% increase over the stock rate of the OEM Marz springs. Now this is just me, but I wouldn't be making any walrus jokes around these guys.

 

I'm more of an average weight guy at 190 lbs., or a tad over 86 kg. riding weight. That's with full armored leathers, helmet, boots, and gloves. The correct fork spring rate for someone of my riding weight -- that is, the spring rate that will ALLOW both laden and unladen sag settings in the correct ranges -- is about .9 kg/mm. That's a 50% increase in rate over the stock springs. Some riders of my weight go slightly higher than this for the track, but being merely a Road Geez, I've selected my rates and target sag settings accordingly.

 

Hubert, I don't know if you think I'm just making this stuff up, or maybe I'm an escapee from a psychiatric ward? . . . . .

 

But may I (once again) suggest giving your attention to the principles of suspension tuning covered here:

 

http://www.strappe.com/suspension.html

 

I sincerely hope this'll clear a few things up?

[jtucker]

Ratchet, do you know if the stock springs are progressive or not?

 

Ducati Monsters are notoriously undersprung as well... somewhere around .69 kg/mm, but they are progressive, which while not perfect, is supposed to help accomodate a wider range of rider weights (I think).

 

According to the calculators I've seen, proper spring rate for me @ ~200lbs (on the Monster) is somewhere in the ballpark of .90 to .95 kg/mm. I'm going to assume that the extra weight of the V11S (somewhere around 100 lbs) would require even stiffer springs on that bike, but I'm not sure.

[Guest ratchethack]

Ratchet, do you know if the stock springs are progressive or not?

Jason, the stock springs are straight rate.

 

By way of continued full disclosure here , I might add that the up-rated replacement springs I'm riding on now are progressives. For purposes of Forum discussion on suspension setup, I've thought it wiser not to "confuse" matters any further than they already seem to be by introducing any further potential controversy. . . . . .

 

For all practical purposes WRT chassis setup, progressive vs. straight rate is irrelevant.

 

FWIW, while I'm very pleased with the Wilbers progressives (rated at .7-1.1 kg/mm -- or .9kg/mm at half usable travel), I believe that progressive vs. straight rate (an argument fought long & hard on this Forum on battlefields of yore as you may recall ) is negligible compared to getting the overall rate correct -- that is, having an overall rate that yields both laden and unladen sags falling within proper ranges. It's the same task in either case, and no easier, nor more difficult either way.

Ducati Monsters are notoriously undersprung as well... somewhere around .69 kg/mm, but they are progressive, which while not perfect, is supposed to help accomodate a wider range of rider weights (I think).

Mfgr's and racers alike have been following trends toward progressive suspensions (a bell-crank, rising rate linkage has been typical on swingarms for decades, as I'm sure you know - V11 Guzzi's being among the rare exceptions ) as well as toward OEM progressive springs. I agree that progressive suspensions and progressive springs do a better job of accomodating a wider range of load. Generally, with the 3 bikes I've re-sprung with progressive fork springs (or is it 4 now?), I've been pursuing the concept that, while my riding weight (including cargo) is for the most part static, they more effectively accomodate a wider range of variable conditions on the road.

 

BAA, TJM, & YMMV

[docc]

Ok!Ok! Enough arm twisting. Where's the link to get the pefect fitting .90 rate springs for the Marz forks. And, again (sorry) what's the peload length for a strapping 190# armoured rider?

[Guest ratchethack]

Ok!Ok! Enough arm twisting. Where's the link to get the pefect fitting .90 rate springs for the Marz forks. And, again (sorry) what's the peload length for a strapping 190# armoured rider?

Docc, I got my Wilbers progressive springs through Todd Eagan at GuzziTech.

 

Email: todd<at>guzzitech.com. He's an Authorized Wilbers Dealer.

 

(see link here): http://www.guzzitech.com/WilbersSuspensions.html

 

and Wilbers Web page link here: http://www.wilbers-products.net/shop/gabelf_motoguzzi.htm

 

(und klicken Sie bitte auf die gewünschte Bestell-Nr. )

 

AUSGEZEICHNET!!!

 

The springs I'm using are:

 

Wilbers Bestllnr: 600-062-01

 

Luftkammer 100 mm - I highly recommend setting Luftkammer (air space) over using oil volume.

 

The stock 110 mm spacers weren't very far off in my case, but I cut new ones that I think were about 4-6 mm either shorter or longer (can't recall now -- dain bramage) to bring the laden and unladen sags more optimally within range. Co-incident with this, since I was no longer riding around on the bottom third of fork travel on the air spring , I was able to pull the forks up in the triples for the first time, and have been running them 8-10 mm.

 

EDIT: I found one of my posts on spacer length. 105 mm yields very nearly ideal laden and unladen sags with the Wilbers springs at 190 lb. rider weight.

 

Have fun, it'll be like finding a whole new world of handling and riding comfort you never knew you had. . . . .

[BrianG]

Jason, the stock springs are straight rate.

 

By way of continued full disclosure here , I might add that the up-rated replacement springs I'm riding on now are progressives.

BAA, TJM, & YMMV

 

 

Progressives......... bastard!! traitor!! non-purist!!

 

Forget all I've said.... none of it applies to progressive springs.

 

For Progressive springs you want 90% free sag at the front and loaded sag dosen't matter. You want 5% loaded sag at the rear. You want the compression and rebound set to full-damping front and rear. And you want the tires at 10 lb front and 8 lb rear.

 

FWIW my Traxxion Dynamics modified Marz forks are using 1.05kg springs for a 220 lb (in full gear) solo rider. My Penske rear shock runs a 500lb spring.

[Guest ratchethack]

For Progressive springs you want 90% free sag at the front and loaded sag dosen't matter. You want 5% loaded sag at the rear. You want the compression and rebound set to full-damping front and rear. And you want the tires at 10 lb front and 8 lb rear.

Now you've done it, Brian. This could set a few selected learning curves back years. . . . . .

 

[mike wilson]

Ratchet, do you know if the stock springs are progressive or not?

 

 

Easy way to tell if springs are progressive or not is to look at the coil. Linear springs will have the same coil (number of turns per unit length) all the way up. Progressive springs will have a coil that changes (progressively....) from one end to the other. The coils will get closer (or further apart...) as you look along the spring. Sometimes it's quite subtle and difficult to spot. Theoretically (I've never seen this in life) it could also be done by changing the thickness of the wire.

 

You can see the effect quite clearly on some older rear shocks, where the springs were dual rate and had a marked change part way along.

 

m

[docc]

Oh, and to add oil to the pie, does the suspension really travel 120mm or is that but theoretical? Looking at the tell tale markings on my forks ( just changed the tire) the travel measures more like 90 mm. How would that change the sag optimums?

[Guest ratchethack]

Oh, and to add oil to the pie, does the suspension really travel 120mm or is that but theoretical? Looking at the tell tale markings on my forks ( just changed the tire) the travel measures more like 90 mm. How would that change the sag optimums?

Docc, as explained in an earlier thread (somewhere - I can't seem to get the SEARCH function to work lately ), the total available travel is real, not theoretical. It's the stroke of the fork from top-out to bottom-out. Though it may (or may not, depending) take a whopper of a jolt to get your fork to bottom-out, there IS a chuck-hole, bump, or other square-edged baddy out there that WILL do it!

 

One of the techniques commonly used to set sags and AIR GAP, which I covered by request in the How To section on changing fork oil, is to put a zip-tie on a fork tube and find the hardest square-edged bump you can find, and hit it while front-braking as hard as possible without lifting the rear wheel off the tarmac. You do this to get a read on how much of the travel y'er actually using. The zip-tie indicates exactly how far the fork went in compression. This allows you to adjust the air gap if necessary to achieve more or less fork travel. I'm currently using up to 115 mm of the available 120 mm. That's about as far as I want to go, and I consider it optimum for my kind of road riding. Serious racer types will set up for a track so they use ALL the travel with some regularlity on a given course.

 

Y'er likely using a lot more than 90 mm fork travel. What y'er looking at on the tubes is the oil trace left from the last bump in the last several miles. The oil trace from that BIG ONE you hit last week will've long gone.

 

For purposes of setting sags and calculating target sags (sag optimums), I suggest use 120 mm total available travel.

 

A quick and easy way to measure the total available travel is to get the front wheel up off the ground and measure the distance between the top of the lower fork castings and the fork scrapers on the exposed fork tubes. The distance is 124 mm. For calculation purposes, I've been using 120 mm, as I believe this is the physical limit of the fork, at which point seals (if they're well-used and so inclined ), will let go due to exponentially rising air pressure.

 

Hope this helps.

[docc]

I was actually looking at the dirt on the unused portion of the fork tube. I do realize there is more travel in the fork than that but was assessing the 'effective range' if you will. It may be a good indication that I don't have my forks set up very well. I have only lightened the oil and set the preload. Unfortunately the soft springs ( even at my street weight of 165#) required increasing the preload length more than desirable.

 

I've read the threads and deliberations on air gap vs fluid volume. Having always used fluid volume, I wonder: with the air gap you are running have you compared the fluid volume used to the specification? Are you running significantly less oil than the spec?

[Guest ratchethack]

with the air gap you are running have you compared the fluid volume used to the specification? Are you running significantly less oil than the spec?

Docc, what I've found is that since it seems practically impossible to get all the old oil out (and I've gone to considerable lengths ), there's no accurate way to know how much oil by volume is left in there after draining.

 

Using the recommended air gap (Luftkammer - don't ya just love the German language?) gives you something MORE than the Guzzi manual's recommended 400 ml per leg. But not a whole lot more, and it varies, since by my experience, I could never drain one side effectively enough to match the draining out of other side. . . . .

 

So if you go by the Luftkammer and y'er careful to pump out all the air as y'er filling, you can be sure to get it spot-on and equal side-to-side with very little fuss.

[docc]

Thanks, I've got a lot of work to do on this suspension.