Progressive Spring Oil Level Question

[twr1776]

I am installing set of new progressive front springs for my 81GS1000GL and have the factory oil amount. The progressive instructions note not to exceed 140mm to the top of the fork for the oil level (springs out/fully compressed). Should I go with the factory oil spec as long as I am not above that level? Or should I set the level slightly below the maximum recommended level? Also, how much does the oil level affect stiffness/damping/sag. I am planning on using 15 Wt fork oil. Ideally, I would like to firm up the front end without making it too harsh. Thanks for any advice.

[SqDancerLynn1]

just use the factory specs

[Nessism]

just use the factory specs

Yup :-D \\/ :-D

[bonanzadave]

Dumb question

Im waiting for my Progressive parts to get here from Bike Bandit. Which is the top or bottom on the springs ? :?

[emjay]

An important factor to note is that the oil level in each side must be equal. First time I did mine I tried using a measuring cup, but I just couldn't get them exactly the same. I used an old dipstick to check it and was easily able to get them to match.

[emjay]

...Which is the top or bottom on the springs ? :?

It doesn't matter.

[bwringer]

An important factor to note is that the oil level in each side must be equal. First time I did mine I tried using a measuring cup, but I just couldn't get them exactly the same. I used an old dipstick to check it and was easily able to get them to match.

Seconded. Oil LEVEL is what's important, not the amount.

It must be the same on both sides and more than 140mm from the top of the fork tube with the springs out and the forks compressed all the way.

If your manual contains a recommendation for level that is more than 140mm, use that. But don't go any higher -- the Progressive springs are made from thicker wire and displace slightly more.

[twr1776]

Thanks for the advice. I am planning to go with approx 5% less than the factory spec and check to see if the level is below the maximum. My manual lists a liquid amount and not a level. The Progressive instructions say that there is no difference on which end goes in first but suggests the close wound side down is possibly less noisy so that is what I will go with. My instructions also do not list a spacer length but I am going for 1 1/2" of sag based on what I have seen in other posts for preload. I will post the final spacer length it so others can use it for a starting point.

[Einar J Skog]

Hi

Service manual says 10,2 inch down to oil level.

[twr1776]

Thanks Einer