It's the pedal cleats stupid.
So there's this clickety clack noise coming off my Cannondale Six13 for a couple months. We're all going crazy trying to track it down. New BB. No dice. Lube the six bolts in the stem/handlebar area. Noise abates then returns. Ay carrammba. Now I'm wondering if it's the headset.
Then yesterday my Speedplay cleat gives up the ghost. I've had a new pair in the drawer since August, so I replace the cleats. *POOF* the bike is as quiet as a Republican after the last election.
Morals of this story:
• When Speedplay says their cleats are good for 5,000 miles, that's about right. These had 8K + miles on them.
• When in doubt, REMEMBER TO REPLACE THE PEDAL CLEATS before you go berserk on other stuff. But this may well be endemic to Speedplays with that tension spring cleat design. Somehow those plastic cleats for Look and other pedals wouldn't seem to be prone to that. But who the hell would ride around with those? Please.
Before you retort 'Duh' remember that this issue baffled the finest minds in the local Hudson Valley peloton, Piermont Bicycle Connection and of course my own towering intellect. Such as it is after too many miles of hammering.