Originally posted by Steele-Bike
How could two 8spd chainrings with the same number of teeth have a different diameter?
I don't think I can answer the "how", but consider this:
A lot of cassettes are coming with a 32 tooth gear. Compare this to a 32 tooth chainring. I am almost certain they are not the same diameter yet they have the same # of teeth.
That said, two 32 tooth chainrings of the same model by the same manufacturer should be the same diameter with minor differences do to tolerences. But, that's Shimano for you (I
won't get into a rant here).
So considering all of the above posts I believe you need to adjust the F. Derail. vertically on your seat tube, then possibly tweak the adjustment screws. Between having 2 rings that are different diameters plus a diff. # of teeth on one ring (compared to your old crank) I think this is where your problem lies.
Patience young Jedi. Or, ditch the indexing and grab a set of friction shifters and never deal w/ this indexing non-sense again!!!