Music boxes, bicycles, and clocks all have one thing in common: GEARS. You might say that gears make the world turn, since they are in so many mechanical instruments. How do they work and how do you know which gears to use? Find out in...

Here's an abstract of a project from Science Buddies that asks you to experiment with bicycle gears and the circumference of the wheel to determine revolutions per minute.

Several good activities here. Look particularly at Wheel Figure It Out (which is the opening page) and Gearing Up. There are answers to the very good questions at the bottom of each.

Are you a budding Lance Armstrong or Greg LeMond? Are you into cycling and speed? Then this is the science fair project for you. In this science fair project, you will determine the best gear ratio for your bike, to get the highest speed...

Exceptionally well-designed site from Exploratorium, the museum of science, art, and human perception. Analyzes the physics of cycling associated with the use of gears, human-powered motion, braking and steering, and drafting.

This site talks about a young man who has started his own business and tells the story of how he started the company "2nd Gear Bicycles." Gives young entrepreneurs a great way to learn about starting your own business.

Very informative site from The Exploratorium about the science of bicycling. You can learn about the development of the wheel, how gears work on a bike, even how brakes were developed. Perfect site for research on bikes.