15lbs and up! It depends upon what the bike is made of. The department store bmx bikes are the heaviest more in the 25lb+ range. If your looking to actually race bmx. A retail bmx is not a good...
if you want a good diamondback bmx bike go for a diamond back alt 2010-2011. it only weighs 21lbs which is super light. the daimondback alt 2011 is about £650 or $1 057.42 USD