Normally I put a new chain on my fixed at the start of winter and its knackered by the spring, normally at 0.75, last spring I put the gauge on the chain and it was still serviceable. After my ride Thursday I noticed there was a slack spot in the chain so i brought the bike in this afternoon for a fettle, I put the gauge on the chain again and its worn but still serviceable, the first thing I found was that I'd pulled the wheel over slightly in the track end, having sorted that out and retentioned the chain I spent a little while playing with the chainring centring on the spider reducing the slack spot and removing a tight spot. I also checked the front wheel rim, its now six years old and getting worn, I put the gauge on it and its at 1.2 mm so OK for now.