I believe its a M14?? cant remmeber, look at ebay, is full of those bolts man. The other thing is that like 95% of the time those bolts are metric so it is not something you will find in home depot.

Advice, go to your lbs the guy might have zillions moving around for sure or call the guys from bike tools etc, they for sure have one.

This is what you are looking for...

http://www.biketoolsetc.com/index.cg...em_id=FS-ACB14

cheers