Cartridge inside of fork
 

Ok, total noobie question on the cartridge. I have the fork cap and spring out on one end. I have the base valve out of the other end.

Does the cartridge unscrew from inside the outer leg or should the cartridge and damping rod just fall out? Is this what Steve B. was talking about when he said 'special tool' ? :confused:

The cartridge is very tight inside, nothing but the damper rod is moving back and forth.

I am changing the fork oil, and attemtping to tune the base valve stack some. I wanted to get the rest of it apart to tune the mid valve using some previous suggestions as well.


*****************NEVER MIND, I GOT IT OUT, JUST A LIGHT TAP...*************

Now to figure out how to get the stopper out of place with the peening... damn...

On shows suspension you drill the peens on the lower guide bushing/ seal head and then unscrew it apart.
I will be tearing into my sachs very soon to do mv work as well.

Try posting pics as you go along. I will do the same.

Rob

Damn, I didn't get it apart. I wasn't sure if the rod separates where the rod stopper it at. It had this funny ring with four small square notches cut out. I could almost grab it with a special pliers for transmission rings, but it kept slipping out.

I didn't want to ruin anything. All I did today was change the oil and fool with the base valve.


As for the base valve, I did: 24 20 16 12 10 10 for a single stage stack. I wanted the bike to ride well and not cave in on rolling/low speed hills, mounds, etc. But I want the high speed to react quickly and let the fork move to absorb a quick jolt/square edge better than it has been.

I filled it with the Honda/Showa SS7 (5wt) oil at 140mm, and ultimately ended up with the compression 10 out and the rebound 6 out. I guess this Honda oil is lighter than the factory whatever they put in.

I took some big hits out in the testing area (neighborhood :eek:) slamming into ditches, concrete square edge culverts, logs, pavement sidewalk edges, etc. and it seemed great.

It is a little divey when I brake hard, ie probably half of the travel is eaten up, but it recoveres well, and corners like its on rails. The general ride height is the same as before.

I know you said MIDVALVE is where I want to be, but short of sending the fork out I don't have this option right now... I don't want to break anything.

I may play with the oil level a little tomorrow. Thanks for all the help.

Don't know where you guys ended up with this, but you don't have to drill anything on either the Marzocchi 45 or the Sachs 48...

The Marzocchi actually comes apart fairly easily, the Sachs we had to make tools to take it apart properly (tried calling everywhere, no one had any to sell- so we made some.)

That peened over crimped part is the hydraulic anti-bottoming device. It's probably a good thing to have on a dirt bike.

And yes, the midvalve could use some love on both of these forks. :)

Do you hae to make the special tool (if so can you post pics) or can you manage without it?

This was going to be my next step and now I am worried that I will not be able to do it. Any advice apreciated

You don't absolutely need the tool, but you have to be VERY careful taking the base valve out without it. The large adjuster screw leads to thin wall form on the base valve - think room temperature butter.

If you want to extract the rebound and mid-valve, you'll need to fabricate the tool, or make a fixture (easy once the cartridge is out of the fork).

Let's get after it - you only have 50 weeks until you rock the Roof!

Haha yep Roof of Africa 2012 started today! And I have the wounds to prove it (mental note to self: no matter how many times you mentally practice something it is not the same when trying it out on the bike! Graham Jarvis makes everything look easy!!)

Today was actually the first time I have ridden since dropping the oil level and fitting the preload spacer (ended up being 4mm thick and a PITA to source). Bike is a bit plusher but still not on the money so will be stripping it down in the next week or so and getting it sorted. Seems I will have to visit my new engineering friend to get the new "tool"

Steve, Will be emailing you in the week

Ok. I put photos up on the website of what we made.

http://www.stmsuspension.com/photos/

having stripped my forks down and removed the cartridge, and springs, and now looking at your tool, is it small enough to use while the cartridge is still in the fork tube? Especially since there is also a sort of washer fitted to the top of the slotted part that your tool fits into making the actual slots quite small?

how easy would it be to make a similar tool using a steel pipe with the slots cut out and a bar welded to the top of the pipe? (i do not have access to a CNC machine that can make pretty tools!)

I'll take some pics and post of the tool I had made.