Single-speed bicycle

From Wikipedia, the free encyclopedia

Single-speed mountain bike

A single-speed bicycle is a type of bicycle with a single gear ratio. These bicycles are without derailleur gears, hub gearing or other methods for varying the gear ratio of the bicycle. Historically, all bicycles were single speed bicycles, specifically fixed-gear or fixed wheel single speed bicycles that had no mechanism to vary the gear ratio or to allow the pedals to coast while the drive wheel moved.

Many individuals looking to improve the efficiency, speed and comfort for bicycle riders developed freewheel systems and gearing systems for bicycles. The term 'single speed' in this article refers to modern bicycles.

There are many types of modern single speed bicycles; BMX bicycles, most bicycles designed for children, cruiser type bicycles, classic commuter bicycles, unicycles, bicycles designed for track racing, fixed gear road bicycles, fixed gear mountain bicycles, and single speed bicycles.

Most Fixed-gear bicycles or fixed wheel bicycles are a subset of single speed bicycles, however it is possible to have a multi geared fixed gear bicycle. Fixed gear bicycles do not allow the rider to coast without pedaling while a single speed freewheel bicycle does. Fixed gear bicycles simply lack any sort of ratchet mechanism that allows the pedals to coast independently of the drive wheel. Both types of these bicycles are, in general, truly single speeds; however, fixed gear bicycles require distinct skills of their riders.

1 Advantages and disadvantages versus multi-speed bicycles
- 1.1 Advantages
- 1.2 Disadvantages
2 Types of single speed bicycles
3 See also
4 External links

[edit] Advantages and disadvantages versus multi-speed bicycles

[edit] Advantages

A single-speed bicycle is generally lighter and mechanically simpler than its multi-geared equivalent. Without derailleurs or other gearing systems, there are fewer parts on the bicycle. The fewer parts allow the bicycle to be much lighter and require less maintenance. Additionally, some parts common to both types of bicycles, such as the drive wheel, can be made somewhat stronger without a corresponding increase in weight. For this reason some cyclists who ordinarily ride geared bikes prefer to ride single-speed bikes during the winter, as the drive chain of a singlespeed bike is more durable in wet, muddy and gritty conditions which would otherwise wear out the expensive components of a geared bike.

Single speed bicycles can also be much less expensive to buy or assemble. Maintenance costs are also potentially much lower when compared to those for multi-geared bicycles. While a single-speed can cost as much as a geared bicycle, a skilled person can assemble them very light and strong for little money or trouble.

The drivetrain efficiency of a single-speed can be greater than today's typical multi-geared bicycles. A straight chainline, lack of chain drag from rear derailleur jockey pulleys, and lack of chainrings ramps and pins all improve the comparative efficiency. As a single rear cog takes less space than the typical 7-10 cogs present on most multi-geared rear cassettes, rear wheels can be built with little or no dish, which is inherently stronger.

Another type of advantage not often admitted by single-speed cyclists is an emotional one. Many enjoy nonconformist feelings taking pride in riding the same roads or trails without gearing systems. Many single-speed cyclists portray the refusal to purchase highly marketed gearing systems as an anti-establishment action. As single speed bicycles have become more common and more expensive, these advantages are being eroded.

better workout for same distance covered
increases muscle strength quicker over same training time

[edit] Disadvantages

smaller range of efficient speeds the bicycle can be pedaled at
typically lower top speed of bicycle
banned from some races and other bicycle events

[edit] Types of single speed bicycles

Typically a reference to a single speed bicycle invokes the idea of a single speed mountain bicycle. However, mountain bicycles, road bicycles, cyclo-cross bicycles, and hybrid bicycles can be made as or changed into a single speed. Mountain bike single speeds designed for trail riding often have a relatively low, or easy and slow, gear ratio. This allows them to climb hills and deal with obstacles and gradients better. Single speed bicycles designed for road riding typically have higher, or harder and faster, gear ratio.

Single speed bicycles and fixed gear bicycles are popular with bicycle messengers for their reliability and durability. Depending on the situation, a messenger may prefer a mountain bike based single-speed, which can be an urban tank, able to roll over almost any obstacle, or a road bike-based single-speed, which is fast and light.

Statements by cycling industry representatives and journalists fueled the perception that major bicycle manufacturers discouraged modern single speed bicycles. However, increased popularity of the single speed has resulted in the design, marketing, and production of many models. In the United States market, bicycle companies Bianchi, Cannondale, KHS, Kona, Raleigh, Giant, Specialized, and Trek all have recently produced and marketed single speed bicycles.

Single speed mountain bikes are typically constructed with no suspension (fully rigid) or front suspension forks. However, as single speed bicycle production by major manufacturers has become more common, a limited number of fully suspended single speed moutain bikes have been produced. However the popularity of "full-suspension" single speeds has been limited by the general impression that the increased weight and complexity of a fully suspended frame runs counter to the "light and simple" image sought by many single speed riders.