Marz Fork service

[Guest ratchethack]

Brian, I'm truly sorry if airing my lack of understanding confused you. As it turns out, the water got a lot deeper than it looked before I waded in. I guess it's what happens when an old moto Geezer runs into what is for me "newfangled" technology (cartridge forks)!

 

FYI - I just got off the phone with an engineer at Spectro. He cleared up a few things. First of all, the viscosity ratings posted on their Web site for their Fork Oil and their Cartridge Fluid (the ones I referred to above) are correct, but they aren't to be used for comparison purposes of viscosity , and are misleading due to the temperatures that ASTM testing requires. Don't ask.

 

He pointed me to the most useful chart for comparison purposes, Spectro Suspension Oils Comparison Chart, a little over half-way down the page at http://goldenspectro.com/oilcomparison1.htm . It shows how to properly compare Fork Oil and Cartridge Fork Fluid with each other, and with other mfgr's. As the chart shows, either their Fork Oil or Cartridge Fork Fluid may be correct for our forks, depending on what you're trying to achieve.

 

Hope this might end up helping you as much as it helped me, and sorry again for the confusion on fork oil. I'm steadily gaining a new respect for the value that professional chassis tuners provide, and will likely have a Pro fully sort mine as you're doing - or at least consult a Pro as I change out fork and shock springs and fluids, possibly revalve, etc. in pursuit of something closer to chassis potential.

 

Thanks for your description of the "working air spring". My previous knowledge came from the pre-cartridge fork days when it was relatively easy to understand. I still no savvy some of this, but maybe it's not critically important that I understand it all anyway.

 

Rgds.,

 

Ratchethack

[BrianG]

Ratchethack:

That's great information, and I'll reference the web-site.

 

As usual, Max's reply, regarding what to use, was "concise", and is as follows:

 

"Light 125/150.

Fork oil is cheap crap, and fork fluid is a precision hydraulic damping fluid."

 

Seems pretty straight forward!

[BrianG]

OK, the last variable that I'm uncertain about is that blue aluminum "nut" on the damper rod. Since it moves quite a bit on the damper rod, is it just a jam-nut to set against the fork cap, or is it for spring preload?

 

I think it's certainly usable for unloading the spring for installation, and then might one be able to get some proload out of it as well??