Physics Of Mountain Bike Essay

Physics of a Mountain Bike

This paper will discuss some of the physics involved in bicycles. Specifically, mountain bikes with suspension. A bicycle is a very energy efficient vehicle. Its wheels allow its rider to make full use of inertia and gravitational potential energy. The basic design of a bicycle has been around for over 100 years and compared to other things, has changed very little. Some of the topics that will be covered are: frames, wheels, suspension forks, suspension frames, brakes and how all these things affect speed, momentum and stability.

Some of the key parts of any bicycle are the frame, forks and wheels. The most common type of bicycle frame is known as the double diamond. It is called this because if you look

By squeezing a lever, the force from your hand is transmitted to the brakes. Rim brakes use rubber pads that press against the rim, hub brakes have metal ‘shoes’ that press against the hub of the wheel and disc brake use semi-metallic pads to press a disc. All of these brakes use friction to slow down the bike. This friction converts forward momentum into heat and as the wheels turn more slowly, the ground exerts a backward force on the tires which slows the bikes forward momentum. In certain cases a lot of heat is generated. One of the first mountain bike races took place at a place called repack hill. The first mountain bikes used hub brakes and they got so hot from use that the grease melted out of the hubs and they had to be ‘repacked’ before each downhill

When mountain biking, these outside forces can rocks, trees or any other number of things. But most likely these are smaller objects in your path. With suspension, the effects of these obstacles are lessened. The shocks absorb the bumps by compressing allowing you to continue in the direction of travel. Energy is conserved. In mountain biking circles there is a saying; the faster you go, the smoother it gets. When you let go of the brakes, your wheels skim the top of rocks instead of dropping into the ruts or washboards. The downside to this is a loss of control. The tires aren’t keeping a constant contact with the trail so when a change of direction happens, either by choice or by chance, the results are not always pretty. The faster you go, the smoother it gets and the greater the force required to stop. Mass times velocity is not fun when applied to a crash. Mike Farrentino in an article in Bike magazine says, “The faster you go, the longer the crash, the greater the force of the impact. Seconds seem like hours, and the clatter and gasp and thud of cart wheeling bike and body parts is not a sound easily forgotten. …In spite of this, whatever any of us say, we all want to go fast….Momentum is the secret key to the universe. It is the rush of joy. It is the heavy hand of gravity. It is the grin of a child, feet off the pedals, bombing downhill on a