I ditched the 2x9 drive train on my 29'er to go with a 1x9 set up (32t front & 12-36t rear). The front ring is a Raceface un-ramped one. The guide is an M-part one.
It's be fine until the last ride out - it was freezing cold and the ground was solid to the point where ruts were solid lumps - the chain must've come off the front ring around 10 times in 2 hours.
The set up is as pictured below.

Does it look right for positioning over the ring?
It's only happened in these freezing conditions, could it be down to the mech getting a bit cold and not keeping tension in the chain allowing it to unship from the ring?

