My question relates to my SS/FG bicycle. I noticed that at one point in the crank/chainring rotation the chain is much tighter (when the drive-side crank is at 3 o'clock when viewed from drive-side). Result is that when I adjust the rear-wheel accordingly, the chain is really (dangerously) loose when the crank is rotated 180 from that position.
[Sugino cranks, Rocket Ring 46t, Surly freewheel 18t]
I tried SB's suggestion/method of loosening all the chainring bolts and tapping/bouncing tool (15mm wrench) on chain to nudge it into position to compensate for the imperfection in the chainring. So I tried really squeezing the chain together, thinking the chainring might just be a little stuck. Still didn't help, the chain remained very tight/very loose.
So, my question(s):
Did I miss something? Any suggestions before I buy a new chainring? (the current chainring and whole bike only have about 200 miles on them)
I've gleened that chainrings often aren't truly circular, but this seems extreme to me. [edit: I'm reasonably sure it's not the freewheel because the tightening/loosening of the chain occurs at the same point on every rotation of the cranks...but feel free to correct me on that.]
Thanks for your suggestions and comments!