Resprung my non-adjustable Marzocchis

[scott_araujo]

I've got an '03 800 Dark.  The non-adjustable Marzocchi forks have always felt too soft so this weekend I re-sprung them.  I got my springs from Race-Tech.  I'm 215# and after talking to Louie at Rece-Tech I decided on the .95 kg/mm straight rate springs.  They don't list a spring kit for the '03 800 but when I spoke to Louie he said the FRSP 3827 should fit my bike.  3827 stands for 38mm outside diameter and appox. 270mm length.

The stock springs are 38mm dia. and 292mm long.  They are a progressive spring.  The new springs are a straight rate spring and a little shorter but they included a nice long piece of T6061 aluminum tubing at my request to cut spacers from.  The top coil on the spring tapers in a bit to a narrower diameter but this wasn't really a problem, they still fit just fine.  The kit also includes some steel washers so the aluminum spacers don't sit directly on the spring or another hard surface that could damage them.

I also swapped the stock 7.5w oil for Bel-Ray 5w to get faster damping.  The stock set up felt a little harsh and over damped.  The manual says the fork legs should take 410cc each but that was way to much.  I only got about 275cc out of each leg no matter how much I pumped the cartridge.  When I tried to put in 410cc there was no air space left at all.  I ended up setting it to 118mm from the top, where I measured it when I took them apart, which was about 300cc.  Probably took a little more than I took out since the new spacers are thinner walled and take up less space.  I cut the spacers to make the combo of spring plus spacers the same height as stock.

The ride is much better now.  With the lighter oil the fork is less harsh and more reactive which is what I was looking for.  Brake dive is largely reduced and the front now matches the back much better than it did.  It takes high speed ruts without jarring the handlebars and mid corner bumps don't upset the tracking any more, it stays on line.  I may still make some more adjustments after I ride it for a while, maybe a few more mm of pre-load once I  ride it for a little longer.  Also, it seems to be sitting higher so the steering has slowed down.  I'll probably move the fork legs up in the triples a little bit to make it sharper.

It's no Ohlins but it's way better than it was and for only about $150 total.

Scott

[BK_856er]

Nice work   

How did your sag numbers turn out, and how is your rear setup?

BK

[scott_araujo]

I haven't checked the sag numbers yet, wife was away for the weekend so no one to measure with me sitting on it. 

The rear is the stock shock with adjustable rebound damping and pre-load.  It feels pretty good but I have a fair amount of pre-load dialed in so I may swap the spring out for a different one.  I've seen some advice against this because the damping can't handle it but if I'm running lots of preload then I'm effectively getting more force out of the spring.  As with the front, better to run a slightly stiffer spring than massive preload.  We'll see how it all goes.

Scott

[the_Journeyman]

I did the same with my non-adjustable Marzoochis too.  Worked very well.  I got a package with a rear spring too and it really settled & smoothed the bike ~

JM

[scott_araujo]

Journeyman, was that rear spring for the stock low end preload and rebound damping only shock?  What weight springs did you get front and rear?  I was planning to take the stock (progressive) spring off and take it down to a local shop to get it measured, then do some graphing with the amount of preload I had dialed in and see what straight rate spring would be just a little higher weight.

Thanks,

Scott

[the_Journeyman]

I had the lowest end of suspension as my was originally a Dark.  My rear was (still is) rebound & preload only adjustable.  I added a kit my Hyperpro that came with front and rear.  I don't even know the rates, it was an e-bay NIB for a M900 and a 180lb rider according to the description.  It probably wasn't the *right* kit for my bike & weight, but for $80 it was a huge improvement ~

JM

[scott_araujo]

Last night I finally got to measuring my sag: 23mm for the bike, 33mm with me on it.  These numbers seemed just a bit low and the forks seemed like they could be a little more compliant.  I cut new spacers about 4mm shorter than the old ones and I took a short test ride.  There seems to be a bit more brake dive but it's not excessive.  The bike still tracks well in corners.  I also need to readjust the back a bit to match.  I'll keep you posted after I get a few more miles on it.

Scott

[CETME]

i Could be totally wrong...but shouldn't the sag numbers be something like:

5mm bike, 30ish mm Rider?

[scott_araujo]

This is the best setup page I've seen and one of the only ones I've seen with actual numbers for free sag AND loaded ride height:
http://www.ohlins.com/Checkpoint-Ohlins/Setting-Up-Your-Bike/Underrubrik_1/

Of course this is a starting point and kind of subjective.  If you like it set up differently and it works for you, so be it.

Scott

[BK_856er]

i Could be totally wrong...but shouldn't the sag numbers be something like:

5mm bike, 30ish mm Rider?

For a rear shock, yes.

BK

[brad black]

Last night I finally got to measuring my sag: 23mm for the bike, 33mm with me on it.  These numbers seemed just a bit low and the forks seemed like they could be a little more compliant.  I cut new spacers about 4mm shorter than the old ones and I took a short test ride.  There seems to be a bit more brake dive but it's not excessive.  The bike still tracks well in corners.  I also need to readjust the back a bit to match.  I'll keep you posted after I get a few more miles on it.

Scott

sounds like the springs are too hard and you have too little preload, if that makes sense.  i'd be aiming for a 0.85 - 0.90 at that weight i think.

did you set the oil height with the springs and spacers out?  you should be able to get 400 or so in ime.

[scott_araujo]

It may be too stiff but that's why I cut the spacers down for less preload.  I prefer a little stiff to a little soft.  I also like stiffer springs, less preload, and faster damping.  The numbers are falling right inline with the specs on the Ohlins page.  That may be a bit stiff for the street but so far I prefer it to the way it was stock.  Since Racetech doesn't list a spring rate for my bike (800 Dark) I looked at the 750 and 900, which were .90 and .95 respectively for aggressive street.  Not seeming to be getting any skinnier lately I went with .95.  I'll see how it feels now, I haven't had much of a chance to ride lately.  Need to put a zip tie on the fork and see how much travel I'm using.

Also, that 410ml of oil per leg is bunk.  My bike it totally stock but maybe I've got some different fork.  I pumped both fork legs dry and was only able to get around 275ml out of each.  At 410 there was almost NO air space at all.  ~275 set it to 118mm height with it fully compressed, the cartridge pumped to get rid of air,  and everything but the springs in.  118 was where I measured it when I took it apart.  No bottoming so I see no need to increase it.  The new spacers are thin walled aluminum tubing and wouldn't really make much difference either way.

Scott

[scott_araujo]

Just a little update....

I took the bike out for the first time in a few weeks today.  Last time was in the rain.  As I was checking the tire pressure I noticed that there was a nice film of crud on the fork tubes.  Most of it was wiped clean by the seals excpet for about 3/4" at the bottom of the fork.  This means the forks are going through almost their full travel in my daily riding so I think I got the spring rate just about right.

Gotta look at the back end now, may need a spring upgrade there.

Scott

[erichan8757]

Hi Scott,
Wondering , does it take a lot of time to take them apart
and put them back together?
what tools are needed?
thanks,

I got a traxxion dynamics spring from front and rear,
set up for 185 (full gear rider)
if anyone is interested in how it'd turn out
i will post a reply soon as i finish respringing them.

e.

[ducatiz]

damn, i have a set of forks for my SS that I want to respring with heavier/progressives like you did and now i know who to call.. email him and tell him you're sending him another customer.

-tiz