I just got a Madone 4.5 and there seems to be an clicking noise coming front the front of the bike. It is not at any regular interval (ie it's not the computer sensor) and happens mostly when I stand during an ascent or when I am pushing a bit ( pedaling against a bit of force rather than downshifting) I have since put clipless pedals on and new Mavic wheels and the clicking still occurs. My bike mech regreased the scewers but still....clicking...any suggestions?