Shimano Nexus
Encyclopedia
Shimano Nexus is a brand of bicycle components which includes products such as epicyclical
gear hubs
, crankset
s, shifters
, brake levers, hub brakes, hub dynamo
s, and a CPU for automatically changing gears. The series is primarily aimed at the "comfort" market such as urban commuters and tourers, and as such is not made to withstand the rigours of off-road or mountain biking
. Unlike the Alfine range of products, neither gear hub of the Nexus-series is disc-brake compatible.
Auto 3 - The hub is fitted with a 3 speed automatic gear system, which utilizes a front hub dynamo to power a CPU that automatically changes the three speed internally geared hub.
Inter 4 - Nexus Inter 4 hubs had four speeds. It has been discontinued.
Inter 7 - The Inter 7 comes in two versions with either a steel
or aluminium
shell, weighing 1860 and 1460 grams respectively, the latter more expensive yet relatively reasonably priced. The gear mechanisms are operated with a Revo Twist Shifter or a simple non-ratcheting trigger shifter and are identical in the two versions, offering a range of 244% with non-even interval percentages of 17,14,17,16,17,16.
Inter 8 - The Inter 8 has interval percentages between the gears of 22,16,14,18,22,16,14, and a total range of 307%, comparable to a road bike derailleur gear systems, but as the other Nexus products, it is designed and intended for urban commuter use. The hub comes in a variety of versions, weighing between 1550 and 1990 grams stripped.
Epicyclic gearing
Epicyclic gearing or planetary gearing is a gear system consisting of one or more outer gears, or planet gears, revolving about a central, or sun gear. Typically, the planet gears are mounted on a movable arm or carrier which itself may rotate relative to the sun gear...
gear hubs
Hub gear
A hub gear, internal-gear hub, or just gear hub is a gear ratio changing system commonly used on bicycles that is implemented with planetary or epicyclic gears. The gears and lubricants are sealed within the hub-shell of the bicycle's rear wheel, as opposed to derailleur gears, where the gears and...
, crankset
Crankset
The crankset or chainset , is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain, which in turn drives the rear wheel...
s, shifters
Shifter (bicycle part)
A bicycle shifter or gear control or gear levers is a component used to control the gearing mechanisms and select the desired gear ratio. Typically, they operate either a derailleur mechanism or an internal hub gear mechanism. In either case, the control is operated by moving a cable that connects...
, brake levers, hub brakes, hub dynamo
Hub dynamo
A hub dynamo is a small electrical generator built into the hub of a bicycle wheel that is usually used to power lights. Most modern hub dynamos are regulated to 3 watts at 6 volts, although some will drive up to 6 watts at 12 volts.-Models:...
s, and a CPU for automatically changing gears. The series is primarily aimed at the "comfort" market such as urban commuters and tourers, and as such is not made to withstand the rigours of off-road or mountain biking
Mountain biking
Mountain biking is a sport which consists of riding bicycles off-road, often over rough terrain, using specially adapted mountain bikes. Mountain bikes share similarities with other bikes, but incorporate features designed to enhance durability and performance in rough terrain.Mountain biking can...
. Unlike the Alfine range of products, neither gear hub of the Nexus-series is disc-brake compatible.
History
In 1995, Shimano rolled out its Nexus line of seven- and four-speed internal hubs. Shimano had manufactured three speed hubs prior to that, and these hubs were at that point rebranded Nexus. In the early 2000s the 8-speed Nexus hub gear was introduced, having three stepped planetary series mounted downstream of each other. The hub was operated with a standard twist shifter. By November 2006, The Nexus range came in several ranges (Inter 3, Inter 7 and Inter 8) providing 3, 7 and 8 speed models respectively.Products
Inter 3 - This hub has three speeds with 36% intervals and an overall gear range of 186%. It weighs 1220 grams stripped.Auto 3 - The hub is fitted with a 3 speed automatic gear system, which utilizes a front hub dynamo to power a CPU that automatically changes the three speed internally geared hub.
Inter 4 - Nexus Inter 4 hubs had four speeds. It has been discontinued.
Inter 7 - The Inter 7 comes in two versions with either a steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
or aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
shell, weighing 1860 and 1460 grams respectively, the latter more expensive yet relatively reasonably priced. The gear mechanisms are operated with a Revo Twist Shifter or a simple non-ratcheting trigger shifter and are identical in the two versions, offering a range of 244% with non-even interval percentages of 17,14,17,16,17,16.
Inter 8 - The Inter 8 has interval percentages between the gears of 22,16,14,18,22,16,14, and a total range of 307%, comparable to a road bike derailleur gear systems, but as the other Nexus products, it is designed and intended for urban commuter use. The hub comes in a variety of versions, weighing between 1550 and 1990 grams stripped.