I have been riding my SingleSpeed almost exclusively for the past 6 weeks.
Two Sunday's ago, several of us got together for a bigger ride, so I pulled out my geared bike to ride.
About 1/3 of the way through, I could not drop down to my granny gear up front, and I paid a price for it. Was DEMOLISHED by the time the climbing was done.
I knew we were going for another big ride yesterday, so on Saturday I pulled out the geared bike again, for a "shake down" ride. It was about 38 degrees out, sunny skies, and the bike performed FLAWLESSLY.
So I ride to the meeting point yesterday, it was about 30 degrees out, and I am noticing some poor shifting again. Both the front and rear derailleur are not going anywhere. No up. Not down. I am ready to bag it, but somebody has some lube, so we pull the cables out of their hangers, goop up the cables, slide the housing back and forth, put the cables bank in their hangers, and shifting is OK, so I go with the group.
It was maybe still right around freezing when we started climbing, and went from about 2,600 asl to about 5,900 asl. The higher we climbed, the worse my shifting got, to the point that I was again stuck in one gear.
As we descended back down, the temps rose dramatically, and the shifting came back.
Do I have a wad of water in my cable housings? If not that, what else could it be?
When I got home last night, I again pulled my cables out of their hangers, hit the cables with some WD, then slathered grease over them, slide the housings back and forth, remounted them, and cleaned up.
Rode it around in my yard, seemed smooth, but I want to avoid this issue the next time I go ride it.