Road Race
In a road race, the weight limit for a racing bike is a minimum of 15 lbs. Cycling speed and acceleration decreases as the bike gets heavier, especially when you are cycling up a steep hill. Shaving a pound or two off your bike could mean the difference between winning or losing a race when the finishing times differ by mere seconds. Despite the slight difference in speed, a lighter bike could cost considerably more.
Handling
Lightweight, 15-lb. racing bikes are more difficult to control than heavier bikes. If you are not a competitive cyclist, judge a bike by factors such as stability and handling, rather than a bike's weight. Consider the bike as a whole. If you ride a touring bike, a heavier bike provides the advantage of greater stability when weighted down with heavy gear.
Body Weight
Heavier riders and mountain bikers prefer more durable and heavier bikes. If you weigh 250 lbs., riding a bike that weighs only 23 lbs. might be dangerous because the added weight could break lightweight components. Even with racing bikes, a heavier cyclist may ride a bike that weighs almost 30 lbs. If you ride over rough terrain and ride hard, choose a heavier bike that can deal with hard use.
Weight of Materials
Aluminum and carbon fiber bike frames are lightweight, but not as durable as steel. Although steel weighs more, full steel bikes weigh only about 4 lbs. more than a lightweight carbon or aluminum bike. This is not a large amount considering the total weight of a bike. Properly constructed steel frames can outperform aluminum frames in terms of handling and performance, despite their heavier weight. Steel is also a cheaper and more durable material, which might matter more than its weight.
