The rear shock preload on my DS650 came loaded like 2/3 of the distance. I tried to reduce the preload but could not turn the two disks, they are frozen together. I tried using a hammer and flathead screwdriver but the shock rotates a little when I strike the disk, reducing the impact. Has anyone been able to adjust the rear shock preload? Did you use a special tool?

 

Look closely, I think you will find a Tab that holds the adjusting nut in place. I noticed that on the front of the DS my brother has, when new the paint stripes show where the tab is located.
I might be off track but take a close look.
Good luck

 

I had the dealer adjust the preload on my back shock. He said that there is a special tool that is needed to adjust the disks. I didn't see the tool but maybe your dealer has it. I also have tried to adjust the peload myself and ran into the same problem hence having the dealer do it. good luck
later

 

I had that problem once on my Tecate. With the rear plastic off I was able to use a huge pipe wrench to adjust it. Worked like a charm. Also, they do make special tools that adjust those discs. I was going to post a link, but I can't remember where I saw that thing at now! If I find it, I'll let you know.

 

I finally found the tool I was talking about. Unfortunately it's not the "exact" one I saw originally and I'm not sure if it'll work on the DS.

Anyhow you can find it @ www.midwestmoto.com
Click on "Online Catalog"
Then "Misc/Tools/Videos"