I have an 06 290 and whilst giving the linkage their monthly re-grease today, and having the shock in my hand, i noticed the spring tension collar was on the last pitch of thread. I remember last month there was more thread showing and it seems it is undoing itself. (Why no lock ring??)

Ive heard about the shocks coming apart, but only on early 06 models (this ones april 06).

I should also say i could turn the collar by hand and turned it about 5 turns and have put a line of tippex to see if it moves again on sunday.

Has anyone else had experience of the collar coming undone as i really wouldnt want it to come completely off.

My 07 shock has a tiny black allan grub screw in the spring collar ring. Make sure you have tightened it to stop the collar from rotating, if it was loose then it might have fallen out.

Shecro replaced my 06 Shock after the base of the shock mounting fell off. The replacement one has the grub screw but the original one did not.

But it might be easier to remove the tensioner ring and drill-out, tap and fit a grub screw yourself.

I

You do need some preload on the spring to hold it. Rear sag(weight of bike) should be 20-30mm.

I do not recall the '06 having a grubscrew, but a drop of blue locktight should do it . I always removed the screw anyway! Never moved!