I was heading to work, got about a third of the way there, when I noticed my chain was either slipping or skipping. It seemed as if it would engage only every other stroke. I thought this was odd given that when I started riding, it was fine and the problem didn't appear until about 5 minutes in.
I can't see anything obviously wrong. My first thought was that the tensioner arm wasn't engaging so that the chain was too slack to properly engage while pedaling. It looked at a bit of a shallow angle compared to my wife's Brompton when I got home. However, I can't be sure.
I had the bike tuned up about a month ago at what I considered the best bike shop in town, and since then, I've ridden it a number of times without incident.
Any idea what's going on? I'm hoping it's not the IGH itself...