A bottle dynamo or sidewall dynamo is a small electrical generator for bicycles employed to power a bicycle's lights — or to charge batteries for electronic devices including cellphones or GPS receivers.
Named after their resemblance to bottles, these generators are also called sidewall dynamos because they operate using a roller placed on the sidewall of a bicycle tire. When the bicycle is in motion and the dynamo roller is engaged, electricity is generated as the tire spins the roller.
Two other dynamo systems used on bicycles are hub dynamos and bottom bracket dynamos.
Read more about Bottle Dynamo: Advantages Over Hub Dynamos, Disadvantages Over Hub Dynamos
Famous quotes containing the word bottle:
“Name me, if you can, a better feeling than the one you get when you’ve half a bottle of Chivas in the bag with a gram of coke up your nose and a teenage lovely pulling off her tube top in the next seat over while you’re doing a hundred miles an hour in a suburban side street.”
—P.J. (Patrick Jake)