Hi Pleiades,

Thanks for the fast reply.. :-)

I googled for 'chatter' and i think that's it. The shocks don't follow the road but just bouncing in a ritme. But i read some articles that chatter happens a lot when the Motogp riders really pushing the bike.
I wasn't really pushing the bike at the moment it happens. But maybe the little bumps in the road triggered the chatter.

The bike is a second hand. I drove 7000 km with it and never checked the shocks. I don't know of the previous owner did some work on them or changed the oil. Or did no maintenance to it.

The milage is 21.000 km at this moment. So... i think it's a good time to do some maintenance on them.
The Kev spacers work great. But i think i'am pushing the bike more and more lately. Maybe its a good idea to change the springs with some progressive springs during the maintenace.

I looked in my maintenace book, but i can't find where the position is of the air gap of the shocks. (I can not find it on google). I always thought it was a closed system. Can you tell me where the air gap i located.