1001 Space Earth Nature History Human World Science and Technology Chemistry Materials Force and Energy Heat and Light Electricity and Magnetism Industry Machines Electronics and Computers Cars and Trucks Railways Ships Aircraft Fishing and Agriculture Undersea Exploration

Choose a Page:How did people pump water in ancie...How does a robot arm work?What is the simplest machine?What is a crawler-transporter used...How does a steam locomotive work?Which were the first machines not ...How did early gramophones work?Who invented the motorcar engine?When was the first bicycle made?What are lasers used for?Who invented the jet aeroplane?*How do a bicycle's gears work?*Is it possible to make a perpetual...How does a roller coaster work? How do a bicycle's gears work? Working the pedals of a bicycle causes a chain to turn cogs on the back wheel. When a cyclist changes gear, a lever lifts the chain from one cog-wheel to another. Small cogs allow the back wheel to turn quickly, making it easier to cycle fast or uphill. Large cogs make the back wheel turn more slowly, which is useful when cycling downhill. A modern all-terrain bike has an average of 21 gears. This helps the rider to get up steep hills.   Previous: Back Book: 1001 Section: Science and Technology Chapter: Machines