I need some help figuring out what bike would be best for my girlfriend. Shes between 5'1" and 5'2" around 120lbs. She currently rides an 06 Gary Fisher Genesister Marlon but its pretty heavy and she occasionally complains of back pain from the rough ride. I want to get her a lighter less harsh riding bike within a $2000 limit. We mainly ride single track thats not to crazy, no big drops or jumps but pretty rooted and twisty. Are "women specific" bikes really women specific? Or are they just mens bikes with women specific colors? Her bike is "women specific" and it weighs more than mine and im a 6' tall man! Any suggestions would be greatly appreciated! Thanks!