Front Forks

[Dan M]

Dan, I just checked. FYI, I put in 105 mm spacers to replace the stock 110 mm spacers. I also tried 100 mm spacers. Again, I think your forks must be different than mine.

 

The stock 110 mm spacers gave unladen sag of 25 mm, laden 38 mm with the Wilbers fork springs.

 

This translates to UNL 21% and L 32% sags.

 

I'll be trying the stock spacers again to see how each set works on the road with the new Wilbers shock.

 

They are different, still Marz 40mm but the later ones have finer dampening adjustment.

 

The Wilbers shock is sweet. Excellent control and plush ride at the same time. I'm thinking of updating my RT as well. (more obsessing)

 

Thanks Ratch.

[Guest ratchethack]

They are different, still Marz 40mm but the later ones have finer dampening adjustment.

There must be more of a difference than damping adjustment gradient.

 

Did you get the same spring I did, (Bestellnr.) 600-062-01?

 

Enquiring minds just gotta know.

[dlaing]

I won't mention here that I was able to slide a medium screwdriver through the shaft slot and over the spacer, and lever the spring down enough to remove the spacer in about 20 seconds - because that might depress you and I wouldn't want to do that after you've been so helpful in sharing your experience. But others might want to try that before getting jiggy with spring compressors and tiedowns.

 

KeS

I hate you

You must have a shorter spring, but if not, then godlike skills, or I was just stupid

[Guest KeS]

I hate you

You must have a shorter spring, but if not, then godlike skills, or I was just stupid

 

Never fear, I'm sure I'll find some other way to gum up the process. But yeah, all my measurements matched yours, with the 6.5" OEM spring. It's just unloaded with the collars spun all the way up, but as you noted you need another half inch of free space to remove the slotted perch. Shoved a taped screwdriver in there and levered it down, no problem. Again, appreciate all your assistance - I'll try to get a shot of the Eibach when I put it back together.

 

KeS

[Guest ratchethack]

UPDATE, Gents!

 

A couple items here that will no doubt be good news, especially for those among us who consider any effort expended on suspension setup to be the devil's work and/or a symptom of extreme Guzzichondria (you know who you are).

 

As has actually been known to happen on occasion, I learned sumpin' new. In this case, I learned it from Todd E at the EMFW II rally. He was able to impress upon me (and actually get me to accept ) two points about the Marz 40 mm USD fork that I had heretofore not understood:

 

1. Even the Big Boys -- those who're "gravitationally endowed" WELL NORTH of the 190-200 lb. I had previously suspected to be the upper limit of the ideal poundage range for the Wilbers progressive springs in these forks -- can, and evidently have, upon repeat occasion, benefitted considerably from these springs in place of the OEM issue springs. Todd was hesitant to put a number to the range because there are so many variables involved in determining a "fit" but he did mention that 220 and 230 lb. guys have provided very positive feedback on 'em. I reckon this is merely a "small wonder", because if you consider the midpoint rating of the Wilbers progressives (.9 kg/mm being the midpoint of the .7-1.1 kg/mm progressive rating), this is a whopping 50% increase over the straight rate OEM spring rating, which I reckon to be .6 kg/mm. My acid test being the ability to get both laden and unladen sags in target range will always be the correct benchmark, but now I understand that this range extends higher than I previously understood in achieving a real-world "fit" on the road.

 

2. EDIT AND CORRECTION: The Marz 040 fork CANNOT be adjusted for preload via the blue anodized adjuster nuts below the fork caps on the cartridge rod assemblies! I had been misinformed by a Pro who should have known better! Cutting new spacers is the ONLY way to adjust preload. The blue nuts are NOT for preload adjustment, and are properly set at 22 mm below the end of the cartridge rod assemblies, the way they come from Mandello.

 

Who says y'can't teach an old dog new tricks?!

[dlaing]

UPDATE, snip

It gets pretty complex, which I guess is why trial and error is best way to find out.

If you got

unladen sag of 25 mm, laden 38 mm

at your 180lb weight with stock 110mm spacer, presumably with nut set to 22mm,

then bubba, at 280 lbs might be putting 40lbs on the front, and up to 100lbs more when braking.

With the Wilbers, he'll probably need to set unladen sag to about 15 mm, and laden sag to about 38mm.

Setting the nut to 32mm might get him close to that target.

Perhaps Ratchet has a better idea of the relationship of preload to sag.

I am guessing Bubba's weight to increase sag about 10mm.

I calculated the 40lbs to increase sag 0.5inches or 12.7mm assuming the springs are 2x 0.714kg/mm, the actual rate and progressivity of the spring, and the angle of the forks, will change the actual sag number, which is why I took 2.7mm off the measurement to come up with the nice round 10mm

Bubba should also have the oil level set a little higher than yours to help keep it from bottoming while braking, but not so high it limits travel.

A heavier rider does benefit more from a progressive spring because of the effects of weight shifting forward.

I think it is better to overset the preload a bit at first to see how close to bottoming one is getting.

But a guesstimation chart for rider weights and preload might look something like this for the Wilbers:

rider weight in lbs ***** mm of blue nut preload using 110mm spacer

80# ***** 12mm

130 ***** 14mm

180 ***** 17mm

230 ***** 22mm

280 ***** 32mm

Again a total guessimate

Only the 17mm at 180 is based on my interpretation of Ratchet's experience, which is still in development, and which without, we would all be much more in the dark.