11 kg Mountain bikes must be sturdy and strong to withstand the hard knocks and rocks of most trails. Parts must be replaced often, so most riders design their bikes with an eye to cost. The frame of Glenn's bike is made of Cromoly, a iron-based metal alloy steel containing chromium and molybdenum to make it harder and more durable. Cromoly is cheaper and more forgiving of blows than other frame materials such as aluminum or carbon fiber composites , though these could reduce the overall weight of the bike. For the other parts of his mountain bike, Glenn chooses not the spend extra money for exotic titanium and ultralight metal alloy tidbits since their price outweighs the performance advantages for him.
Many mountain bikes have suspension systems to cushion the rider from bumps on trails.
The shock absorbers are either pieces of elastomeric polymers or a hydraulic system, within legs of steel or aluminum metal . Glenn's bike also utilizes a carbon fiber beam to support the seat and dampen shock through an elastomeric shear layer within the beam. All rights reserved. Weight is balanced with cost to determine the final materials in a bike. At 8 kg, Glenn's bike is light, yet durable and dependable.