This is a cross post from the Tech Forum>Suspension board.

My ride is a 2004 FLHRS Road King Custom with about 52k on it. Stock front end, recently changed fork oil. Installed 12" Progressive 412 shocks at around 45k, replacing the stock 12" airshocks - love em - ride is much more compliant, absorbs bumps way better, back is happy now.

Problem is when I'm mid-corner in a fast sweeper and on the gas or neutral throttle the front end chatters and doesn't feel very planted. The good news is that it doesn't wander at all or otherwise drift off line - just feels like crap and doesn't inspire confidence. I could live with it, but would prefer to get rid of the chatter, especially since I'm concerned that it probably isn't doing my front tire much good (looking a bit cupped).

I'm pretty sure the chatter is a result of the new shocks, since that is exactly when it showed up. My theory is that the softer shock rate on the back effectivel lowered the back/raised the front/changed the geometry, and now my front forks are running at or near their full extension, resulting in the unplanted front end feeling. Or maybe the old fork springs in front were already shot (52k miles might do that), and the new shocks simply are calling attention to that.

So before I go out spending money I thought I'd lay this out here and see if anyone else has experienced this, and done something to fix it that worked. Thanks for sharing your experience.