I have an XS Blue Norcross for sale. It has a 51.5 top tube. I am 5'4" and it fit me great. I have it listed in the classified forum with specs. http://cowbell.cxmagazine.com/forum/topics/blue-norcross-cyclocross....
Thanks for the reply. I think that it may be a touch big for my son and a little more than I was looking to spend for his first cross bike.