BubbaDog

After taking my new ride out last weekend, I noticed an unnerving quirk about the Ritchey WCS crankset wanting to shift by itself from the middle chainwheel to the granny. This happens when I'm on the third largest rear cassette sprocket or above, and the only way to prevent it is to index the FD so it basically holds the chain against the center sprocket on the crankset. If I index the FD so it's centered on the chain, the chain will drop to the granny in short order. I noticed that the WCS crankset has a number of teeth on the middle and large chainwheels 'shaved down' in height, only about half as high as a normal tooth. Is this allowing the chain to walk off the middle chainring when I shift to a sharp angled chainline from front to back? If so, I guess I need to either replace the whole crankset (to one with all full height teeth) or at least the 52/42 chainrings. Don't know if it makes any difference, but the cassette is a Shimano 105 12-27 and the chain is a Shimano Ultegra 10 speed chain. This stinks on a brand new ride, any help or insights are greatly appreciated....

B'Dog