I have had a metal to metal rattle on my 05 DS650X at about the 2000-4000 rpm range since it was new, it was really starting to drive me crazy. Well I finally found it, it was the factory installed skid plate vibrating against the frame. Just thought I would pass along the info just in case anyone else was having the same problem. It looks like I'll have to run a few strips of thin rubber between the frame and skid plate.

 

My gf 400 outlander has had one also around 35 mph that have not been able to linpoint sounds like the exhaust heatshield but couls not find anything loose may try look at plates under in the spring is a bit too much snow built up under now. (But rattle is gone) [img]i/expressions/face-icon-small-smile.gif[/img]