Had LBS swap from Ultegra double crank to the WCS. Shop said it'd need a new FD. After two return trips, they figured out the problem was that the FSA FD they'd installed was a triple. Said they'd installed an Ultegra triple FD and it was working now. Picked it up and it's better but rubs the FD at either end when shifting out of the middle 5-6 cogs. Shouldn't this be a fairly easy installation?