Hub Gear Article Index for
Hub 		Website Links For
Hub 		 

Information About

Hub Gear
  CATEGORIES ABOUT HUB GEAR
   
bicycle parts
   
gears
   
APPAREL
BABY
BEAUTY
BOOKS
CAR TOYS
CELL PHONES
DVD'S
ELECTRONICS
GOURMET FOOD
GROCERIES
HEALTH & PERSONAL
HOME & GARDEN
JEWELRY
MUSIC
MUSIC INSTRUMENTS
OFFICE PRODUCTS
SOFTWARE
SPORTING GOODS
TOOLS & HARDWARE
TOYS
VIDEO GAMES
SHOPPING HOME
MORE SHOPPING...



Hub gears or '''internal-gear hubs''' are a type of Gear system used on Bicycle s.
Hub gears are used mostly on Utility Bikes and various types of small wheeled bicycle, such as Folding Bikes . Hub gears work by internal planetary or ''' Epicyclic Gearing ''', which means that the outer case of the hub gear unit (which is attached to the spokes) is made to turn at a different speed relative to the rear wheel's Sprocket depending on which gear is selected.

In the United States and United Kingdom , hub gears are less common than Derailleur Gears which are the dominant gear system on most modern bicycles in these countries. In most of continental Europe, however, hub gear systems are dominant. Hub gear systems have in the past also been used on Motorcycle s, although this is now quite rare.

Unlike derailleur gears, where the gears and mechanism are exposed to the elements, hub gears are enclosed within the hub of the bicycle's rear wheel. Gears are changed by a cable which is tightened or loosened by a lever or twist grip on the handlebars.

Hub gears were invented in 1903 by an English company Sturmey Archer , and by the 1930s they had become common on bikes across the world. Their popularity has been much diminished by Derailleur Gears which, since the 1950s , have become the most common type of gear system on bicycles, due to their lower price and wider gear range, although hub gears have undergone a small revival in recent years.

Though most hub gear systems use one rear sprocket, SRAM 's DualDrive system combines an epicyclic hub with a multi-speed rear derailleur system to provide a wide-ranging drivetrain concentrated at the rear wheel. The system is useful for Folding Bicycle s (where a multiple front chainset could run afoul of the bike's folding mechanism) and in Recumbent Bicycle s and Freight Bicycle s (where small wheels and/or increased weight require a wider range of gears with smaller individual steps between each ratio).


ADVANTAGES


  • The main advantage of hub gears is that because the mechanism is enclosed within the hub, it is not exposed to dirt or weather. This means that, unlike derailleur gears, hub gears need very little maintenance and are very reliable, making them very suitable for Utility Bicycle s.

  • The other main advantage is that the gear can be changed when the bike is stationary, which makes them suitable for riding in city traffic with lots of stops and starts.

  • Bicycles built with internal hub gears instead of derailleurs also are less vulnerable to damage in shipping.

  • Shifting is exponentially smoother than any external rear derailleur.



DISADVANTAGES


  • The main disadvantage of hub gears is that, because of the limited space available in the hub, they have a far more limited range of gears than derailleurs. Traditional hub gear systems have only three or four speeds. Recently, however, seven and eight speed internal hubs have become common and models are available which have as many as fourteen speeds.

  • Hub gears are also heavier and more expensive than derailleur gears.

  • They are also claimed to be less efficient than derailleurs, however this is only when comparing with a clean derailleur system which has little wear.



SEE ALSO



EXTERNAL LINKS