695 forks weird compression damping

[suzyj]

I'm putting 998 forks on my 695, but this isn't about that - because it's taking longer than anticipated to gather all the bits required, I figured I'd take some time to improve my 695 forks as much as I could inexpensively, to ride in the meantime.

My main issue was sag - I fixed that by putting some 5/8" washers between the spring and the plastic spacer tube.  It works very well.

I also put 10 wt oil in, in the hope of reducing the rate at which the forks dive under brakes.

While I had the spring out and was putting the new oil in, I noticed some very weird behaviour from the damping rod.  The compression damping on my 998 forks is constant.  Pushing the rod in, you get a constant force back.  The same thing on the 695 forks has the rod practically falling with very little or no damping, then suddenly it's as though the damping turns on, and it's heavily damped for maybe the last 40-50mm of travel.

Is that normal?  I first thought something was broken, except that they both exhibit the exact same behaviour, and I can't for the life of me think of a (failure) mechanism that will cause that (okay, I pumped and pumped for twenty minutes thinking there was air stuck in it, before thinking it through, but you get my gist).

I'd appreciate some guidance.  It certainly explains the penchant for diving that my forks have, as well as the sudden change in response that I get in corners - I thought the forks were bottoming out - looks like it's really this sudden change in compression damping.

[Howie]

Since I can't really feel compression on your fork it is hard to verify what you feel is normal, but compression is lacking on those forks.  Since what you are doing is temporary just correcting sag is good, but better is proper linear springs for your weight.  You should post in your local board for recommendations on oil weight, which helps fix the compression problem.

[suzyj]

The stock oil was 7.5 wt (according to the service manual, anyway).  I refilled with 10 wt, to the same level as indicated by the service manual (104mm).

I toyed with swapping the springs I'd just put in my 998 forks (0.9kg/mm) into the 695 forks, but decided that as the lengths are different it would require too much fiddling with spacers to find the right preload.

The feel has certainly improved.  I think the main thing that's done that is adding spacers to correct the sag.  That means that the neutral point on the forks is further away from point where the damping suddenly changes, so I'm not hitting it on every corner.

Anyway, this has convinced me of the sense in putting the 998 forks on, so I'll be moving ahead with that fairly quickly.