correct amount of fork oil = incorrect level???

[Guest]

Rebuilding the forks on a 84 GK. They're the 41mm ones. Anyway - I completely disassembled the forks so all of the oil was drained out. The GS1100GKE supplemental manual says the fork capacity is 363 ml. So after putting in that much oil I went ahead and measured the oil level out of curiosity. The manual says it should be between 139 and 140mm. It's not even close. It is way lower than that. The ruler I used is about 160mm and it didn't touch the oil.
I have a progressive spring installed. They're longer than the original so it should displace more oil.... I'm holding the fork straight up and down when I measure the level. So my question is do I continue to add oil until the level measures 140mm? If I had just swapped springs I would have added oil until it was at the correct level (after emptying as much of the old oil as I could).

So what do you guys think? Is there any danger in just continuing to add oil until the level is correct?

[d_hoffman]

never mind - answered my own question

I see my mistake now. When you measure the oil level you're suppose to take the spring out and and completely compress the inner tube.

Color me embarrassed. (but I learned something today so all it not lost)

[DPage]

It's more important to have the level right than the volume. I use the volume as more of a suggestion, then use a Softsoap pump with the tube set to the right length. Set it on top of the fork tube and pump away until gets to the right level.

[d_hoffman]

Good suggestion. I'll try that.

[Steve]

Yep, the level will depend on just how dry the forks were when you filled with the recommended amount.

One reason the level is so critical is that the air that is trapped in there compresses and the fork is compressed.
Different oil levels will mean that the air that is compressed in the two fork legs will be compressed at different rates,
changing the effective spring rate for that leg. Different spring rates are not all that good.

.