My first build with the help of my cool LBS. New 6700 Group. Upon the first test ride, there's a peculiar sound [like a creak] occuring when pedaling/cranking. We checked the bb. We tightened the cranks, chain rings etc. It's a very different sound. It also occurs while coasting and pedaling backward. It does not occur while coasting and NOT pedaling. Could it be the BB? My LBS guru tried adjusting and tightening just about everyhing. I tried to "work it out" for a few laps around the neighborhood. The only time it goes away is when I get out of the saddle and crank hard. When I sit back down it returns. Anyone with any advice?