You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
Had a wee issue just at the top of Innerleithen the other day. Seems my rear mech is knackered - the arm would not spring back (tried it with chain off etc):

This ended up with me freewheeling all the way down again as the chain kept coming off.
It is a 10 speed XT clutch mech.
Is this fixable? The spring looks OK and the clutch is still making a difference to tension.
I have tried giving it a good dousing in WD40 to see if it was gunked up but this has not fixed it.
Check that the lug on the rear mech is engaging with the gear hanger correctly - it may have slipped off or hasn't been assembled correctly. Had this when I rebuilt a bike having been dissembled to take on a plane - couldn't work out why it wouldn't work.
Had this the other day with same mech. Unscrew the clutch bit to get at the spring and you’ll probably see it’s a bit seized. Tiny bit of oil and a wiggle and it’s good to go
After dismantling the whole thing entirety, behind the jockey wheel I could see the spring end had popped loose. But by this time I had put my spare one on.
Just in case someone is googling this issue.