I've scoured the intertubes and searched the forums but can't seem to find out what the stock front fork spring measurements are (internal diamter, external diameter, length).
Oh, mighty Ducati Monster Forum, please give me an answer! [bow_down]
For now, you get the standard tech answer....
Which year and model of Monster, or more specifically, which forks do you have?
I'm guessing you're looking to swap them out. The easiest thing to do is just take one out and measure it. I did this with my '03 800 Dark since I wanted new springs and no one listed them.
Scott
Quote from: Speeddog on November 09, 2009, 08:09:20 AM
For now, you get the standard tech answer....
Which year and model of Monster, or more specifically, which forks do you have?
Woops- silly me: 2002 620, i'm assuming whatever's stock in them inverted things
Quote from: scott_araujo on November 09, 2009, 09:46:10 AM
I'm guessing you're looking to swap them out. The easiest thing to do is just take one out and measure it. I did this with my '03 800 Dark since I wanted new springs and no one listed them.
Scott
Yep, gonna swap. But before I take it to a shop and pay them to open them up to measure (since I don't have the tools or a front stand) I thought I'd try to find the info I needed.
If it's stock you should be able to get a good response from someone who knows here on the board. If you don't have the tools it's tough to pull it all apart.
Scott
That's what I'm keeping my fingers crossed for. I'd hate to spend so much money to go into the shop for a few numbers.
We'll see if anyone knows and respond [popcorn]
Scott:
I believe the M620 and the M800 used the same non-adjustable 43mm Marzocchi forks (344 and 345.2.010.1A).
Did you record your spring info?
My WOrkshop manual only says 130mm travel, 0.410 cu dm (cm?) of fluid and to replace the springs if they measure 270mm overall, unloaded.
R
I'll see if I can get the exploded diagrams for the '02 620 but yeah, I think it's the same fork.
Here's my original post with some measurements: http://ducatimonsterforum.org/index.php?topic=22402.0 (http://ducatimonsterforum.org/index.php?topic=22402.0)
I have the stock springs and spacers sitting in the garage, I can measure whatever you want from those. You need the right spring rate and outer diameter but as you can see from my post, overall length varies and is easily accomodated by the spacers you cut.
Scott
Thanks, Scott.
I'll be replacing my M800 springs with linears later this winter. I have an old RaceTech post that indicates the M800 stock spring rate is 0.686 kg/mm, which, if true, means Ducati specced different rates for the 800 and the 620, see below. On the other hand, RaceTech never did have good info on the M800, and since the stock spring IS a progressive spring, that number is meaningless.
Codds, I found the following post in TOB:
"I have an email from Marz USA telling me the stock spring on my 02 620 dark is a .45, dual rate spring. I did not even know anyone made such a light spring, but that certainly explains some of the crappy handling and too high sag.
I'm also being told that Marz has replacement springs in various weights ranging from .85 to 1.0, but they are dual rate springs and variable width springs. At one end they have an ID of 27.5mm at the other, 23mm. OD is 38 and 32 and overall length is about 362mm. All of these measurements came from a .85 spring they had on the shelf for the 43mmRAC fork that Marz assured me would fit in my oem fork."
Quote from: battlecry on November 09, 2009, 01:51:39 PM
On the other hand, RaceTech never did have good info on the M800, and since the stock spring IS a progressive spring, that number is meaningless.
Precisely. And Ducati swaps fork parts around a lot so unless you actually measure what you have it's suspect info.
The calculator on RaceTech is pretty good for forks at least. If they don't list your bike find another Monster that weighs about the same and use that one to figure your spring rate. There's still variablity based on the riding style which you plug in which is subjective but it's in the righ neighborhood.
The rear shock is another matter, diff Monsters have very diff setups. There are three I know of from the early Monsters (hoop), the early 2000's (dogbone linkage), to the present 696 incarnation (laydown). If you have one you can't use a calculator for the other.
Scott
Woohoo! Thanks everyone! This certainly helps a lot!
I looked at the exploded diagrams for both bikes, all major parts of the fork are the exact same part numbers: fork sliders, fork tubes, dampers, springs. So the springs are exactly the same, let me know if you need more specs than there are in the other post. You can also use the same springs from RaceTech that I used, just get the spring rate for your weight and riding style.
Scott