How Do Gears Work On A Bike

For example a 21 speed bike has a triple chainring in the front and seven rear cassette gears.
How do gears work on a bike. Think of it like this. You can t know the gear range of a bike by the number of gears it has. There s no use in buying. Cycling gearing can be confusing.
This video simplifies all the terms and explains how your gears impact your riding. Part of the problem of a hub gear is that it adds weight at one end of the bike which can lead to unbalanced handling. Instead of touching directly and rotating in opposite directions each pair of gear wheels is connected by a flexible metal chain kept taught by a springy lever and gear shifting mechanism called a derailleur so they turn in the same. The number of gears a bike has is figured by multiplying the number of front chainrings by the number of gears in the rear cassette.
Play around with the gears. A bike with 30 or more gears is not an indication of a machine designed to break the land speed record any more than a bike with only a single gear assuming similar ratios. Bikes have two sets of different sized gears on the wheel you pedal and the back wheel. You just need enough of a range.
It s true that a bike with more gears often has a wider range than one with fewer gears but not always and even if it does you don t necessarily need the widest gear range possible.