I have a Dawes Lightning DLX I purchased about 2 years ago for my son who wanted to ride with dad and made one ride and discovered it hurt too much. So the bike has been in my garage and has maybe 15 miles on it. I bought it from bikesdirect, one of those ebay vendors. I think the frame size is 48. Seems they might have re-badged it to Motocebane now but it looks a lot like this
http://www.bikesdirect.com/products/motobecane/miragesport.htm
It was about $320 new. Would make a good cheap bike for a growing kid. Come get it, I live in central CA near Fresno.