I'm looking for my first road bike to get into amature racing ( i'm an old BMX guy) I tested a cannondale six carbon 5 / Trek Madone 4.5 and a Specialized Roubaix. Help!!! I want to go riding this weekend and cant make up my mind
Note the the Roubaix is a "sportive" bike - as I understand it the Allez is the out-and-out race bike in the Specialized line. Many other manufacturers do something similar (Giant has the Defy sportive line, and the TCR race bikes, for instance). A sportive bike is a bit more comfortable and less twitchy, but less stiff (which supposedly matters in hard acceleration).
The differences are subtle, and you can race a sportive bike - plenty of people do. But you should probably give both a try to see which style you prefer.
Rest assured that whatever bike you buy you will a) start dreaming of bits and pieces to add to it, b) you'll want a brand new bike, and c) neither a nor b will make you go substantially better in races!