Part of the ride? Bull.

It's probably a case of your ring not being round enough or being off center. Get your bike up on the stand (or however it is you get the wheels off the ground to work on it) and slowly rotate your cranks. I'll bet you find that at one or two positions the chain is really tight. That feeling you're getting is actually a combination of the chain binding and the chain fluttering as it hits/leaves the tightest-most part of the rotation.