An autobike or automatically geared bicycle is a bicycle with a derailleur or internally geared hub (transmission) that shifts gears without intervention from the rider.
An autobike or automatically geared bicycle is a bicycle with a derailleur or internally geared hub (transmission) that shifts gears without intervention from the rider.
The CSA Autobike Classic was the first commercially sold autobike and was equipped with a system of centrifugal weights on the rear wheel with a rear derailleur attached to them. [1] When the rider started pedaling it would cause the weights to spin outwards, which shifted the derailleur to a higher gear. When the rider stops pedaling and the bike comes to a stop, the weights would return to the center position, shifting the bike into its lowest gear so it is easier to get started again. The Autobike was featured on several infomercials in the latter half of the 1990's. CSA, the maker of the Autobike, eventually went bankrupt. [2] Also of note was the Trek Lime from the 2000's. It used an internal 3-speed hub gear that was electrically shifted based on the rider's speed. Power was provided by a dynamo on the front hub. [3]
Current autobike designs of the 2020's build on the principles introduced by the Trek Lime. The front wheel uses a hub dynamo to generate electricity. Wires connect the dynamo through the frame to the bottom bracket area where it joins a small onboard computer with sensors that detect the rider's speed and cadence. The computer uses this information to actuate a motorized shifter mounted on the rear wheel's hub gear to change the gear ratio. The rear hub used is the Nuvinci N360 CVP which is a continuously variable transmission using a planetary gear system.
A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered or motor-assisted, pedal-driven, single-track vehicle, with two wheels attached to a frame, one behind the other. A bicycle rider is called a cyclist, or bicyclist.
A mountain bike (MTB) or mountain bicycle is a bicycle designed for off-road cycling. Mountain bikes share some similarities with other bicycles, but incorporate features designed to enhance durability and performance in rough terrain, which makes them heavier, more complex and less efficient on smooth surfaces. These typically include a suspension fork, large knobby tires, more durable wheels, more powerful brakes, straight, extra wide handlebars to improve balance and comfort over rough terrain, and wide-ratio gearing optimised for topography, application and a frame with a suspension mechanism for the rear wheel. Rear suspension is ubiquitous in heavier-duty bikes and now common even in lighter bikes. Dropper seat posts can be installed to allow the rider to quickly adjust the seat height.
A derailleur is a variable-ratio bicycle gearing system consisting of a chain, multiple sprockets of different sizes, and a mechanism to move the chain from one sprocket to another.
A hub gear, internal-gear hub, internally geared 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 shell of the hub gear, in contrast with derailleur gears where the gears and mechanism are exposed to the elements. Changing the gear ratio was traditionally accomplished by a shift lever connected to the hub with a Bowden cable, and twist-grip style shifters have become common.
A touring bicycle is a bicycle designed or modified to handle bicycle touring. To make the bikes sufficiently robust, comfortable and capable of carrying heavy loads, special features may include a long wheelbase, frame materials that favor flexibility over rigidity, heavy duty wheels, and multiple mounting points.
In mechanical or automotive engineering, a freewheel or overrunning clutch is a device in a transmission that disengages the driveshaft from the driven shaft when the driven shaft rotates faster than the driveshaft. An overdrive is sometimes mistakenly called a freewheel, but is otherwise unrelated.
A utility bicycle, city bicycle, urban bicycle, European city bike (ECB), Dutch bike, classic bike or simply city-bike is a bicycle designed for frequent very short, very slow rides through very flat urban areas. It is a form of utility bicycle commonly seen around the world, built to facilitate everyday short-distance riding in normal clothes in cold-to-mild weather conditions. It is therefore a bicycle designed for very short-range practical transportation, as opposed to those primarily for recreation and competition, such as touring bicycles, road bicycles, and mountain bicycles. Utility bicycles are the most common form globally, and comprise the vast majority found in the developing world. City bikes may be individually owned or operated as part of a public bike sharing scheme.
Sturmey-Archer was a manufacturing company originally from Nottingham, England. It primarily produced bicycle hub gears, brakes and a great many other sundry bicycle components, most prominently during its heyday as a subsidiary of the Raleigh Bicycle Company. In the past, it also manufactured motorcycle hubs, gearboxes and engines.
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.
A fixed-gear bicycle is a bicycle that has a drivetrain with no freewheel mechanism such that the pedals always will spin together with the rear wheel. The freewheel was developed early in the history of bicycle design but the fixed-gear bicycle remained the standard track racing design. More recently the "fixie" has become a popular alternative among mainly urban cyclists, offering the advantage of simplicity compared with the standard multi-geared bicycle.
A freehub is a type of bicycle hub that incorporates a ratcheting mechanism.
Bicycle gearing is the aspect of a bicycle drivetrain that determines the relation between the cadence, the rate at which the rider pedals, and the rate at which the drive wheel turns.
A hydraulic bicycle is a chainless bicycle that transfers power to the pedals by means of a liquid passing through tubes from hydraulic pump to hydraulic motor and back.
A belt-driven bicycle is a chainless bicycle that uses a flexible belt, typically a synchronous toothed design, in order to transmit power from the pedals to the wheel.
An electronic gear-shifting system is a method of changing gears on a bicycle, which enables riders to shift with electronic switches instead of using conventional control levers and mechanical cables. The switches are connected by wire or wirelessly to a battery pack and to a small electric motor that drives the derailleur, switching the chain from cog to cog. An electronic system can switch gears faster and, because the system does not use Bowden cables and can calibrate itself, it may require less maintenance.
Bicycle drivetrain systems are used to transmit power on bicycles, tricycles, quadracycles, unicycles, or other human-powered vehicles from the riders to the drive wheels. Most also include some type of a mechanism to convert speed and torque via gear ratios.
A motorcycle transmission is a transmission created specifically for motorcycle applications. They may also be found in use on other light vehicles such as motor tricycles and quadbikes, go-karts, offroad buggies, auto rickshaws, mowers, and other utility vehicles, microcars, and even some superlight racing cars.
A gearbox bicycle is a bicycle that uses a gearbox to convert torque and rotational speed from the power source, usually the rider's legs, to what is desired at the drive wheel. The gearbox is usually incorporated into the frame near the crank, and it may be used in addition to or instead of derailleur gears or a hub gear. Cited advantages include improved shifting performance, protecting the gearing from damage and exposure to dirt and moisture, as with hub gears, plus locating the additional mass between the two wheels and on the frame where it may be suspended, unlike with hub gears.