Originally Posted by
fixedpip
If the ring looks warped I wonder if its not sitting on the spider correctly due to a burr or just needing a little tap to seat itself correctly. Either way your mechanic should be able to diagnose correctly.
My own experiences with Sugino 75 components are that they are top notch precision parts, that fit together perfectly. The machining of all the parts are excellent, and there are no no leftover burrs or the such. I have 4 Sugino 75 chainrings, and they are perfectly round and fit perfectly flat on the crankarm spider. Cheaper chainrings like Sugino Messenger and FSA are less perfect.
As far as the bottom bracket is concerned, I agree with you that it is most likely too tight. Also, the problem could be with the frame itself, if the bottom bracket shell threads are not aligned and the bottom bracket cups are not square.