One liter of water weighs one kilogram (2.2 lbs). Two large waterbottles (about 20 oz each) hold about 1.5 liters, around 3 lbs. Does your bike handle any differently with full bottles? I've never noticed a difference.

Don't buy a bike based on weight. I switched from riding fancy Italian criterium bikes to US-built Treks because I noticed a significant difference in handling. The carbon fiber Treks take fast corners like they are on rails. The older Italian frames handle like sh*t in turns (haven't tried any recent Italian frames, though). Anyway, keep trying out bikes until you find one that makes a difference.

- L.