Different Chain Tensions at Different Points
When I first got my Dawes SST AL and gave my chain absolutely no slack, I found that I would be able to pedal until my drive side is at about 12 - 2 o'clock. At this point, the chain tension was so tight, that I would not be able to pedal. Then, I loosened the chain tension a bit and the pedal can spin, but not freely. When I got to that same spot, I would get a lot of friction and the chain gets a lot tighter. I have no idea why this is happening.
At first I thought maybe it is my freewheel because it's a generic freewheel, but it occurs at the same spot everytime, so maybe not.
Then I thought maybe it's the chainring. Maybe the chainring is not a true circle and like an oval or something. Does anyone think I am correct?