Suspension for '03 955i

Hi Khulka - On relatively smooth pavement, I have no complaints. But then if all pavement was relatively smooth, we wouldn't need much in the way of suspension, would we? ;D

I'd say the number one problem is as I mentioned in the previous post. It simply doesn't handle bumps well, low speed or high speed. I started with all the adjustments in the mid range. I added some preload to get the sag right (about 1 inch).

Around town it just feels stiff and a little harsh (best way to describe how I think it should feel is firm but supple). I thought that at speed it would work a little better. But up on the Los Angeles Crest Highway and surrounding roads, there are a number of what I'm guessing are mild frost heaves - Lines of discontinuity that are perpendicular to direction of travel. they are probably only an inch or so high, but pretty sharp edged. And they frequently occur in the corners (since so much of the Crest is corners anyway). When I'm leaned over going over one of these ridges (not scraping anything, but getting out closer to the edges of the tires), it's like the suspension doesn't move at all. It feels like the front tire is lifted off the ground for a split second, and then comes back to the pavement an inch or so to the outside of the corner. I backed off the compression damping 1/4 turn at at time. This helped, but I ran out of adjustment before the problem went away. This phenomenon is currently my limiting factor (on that kind of road, anyway). It just feels a little too freaky, like the next time the front is just going to wash out altogether. I would think that it was just the fact of bing leaned over that far limited suspension compliance, but I get pretty much the same feeling when going over these ridges straight up. It's just not so freaky feeling since you're pointed in a straight line.

Another symptom is accelerating in a straight line through mildly bumpy pavement. It can start a little headshake. It has never turned into a full blown tankslapper, but I don't want it to. I considered a steering damper, but I don't want to mask the problem.

I really liked what Race Tech did for my Bandit, but they don't make valve kits for these years.

Any other thoughts? ???

Hi Khulka - Correct me if I'm wrong, but the preload adjustment modifies the spring length and therefore the sag. But the rebound and compression adjustments only modify the damping (the force acting to retard the sping action). So soft compression damping and stiff rebound damping would allow the fork to compress easily, but they would extend more slowly. So over a series of stutter bumps, the forks could compress more and more. And over a single bump, the forks could compress easily over the bump (maybe even overshooting it), and the stiff rebound would keep it from extending back out to follow the back side of the bump, maybe keeping the wheel airborne. Either way, my task is the same. Try moving compression and rebound damping together instead of just dialing in less compression damping.

:-\