I've got a Shimano Deore 3x front derailleur and it works perfectly fine while warm.
But after a ride in cold (about -10..-15 C) there is a problem in shifting up: first time I pull the lever it goes without any tension - like the cable is torn - and nothing happens. The second time it works fine.
Downshifting is ok, and rear derailleur works well too. So: do I need to worry and what is the reason for this?