A chainless bicycle or shaft-driven bicycle is a bicycle that uses a driveshaft instead of a chain to transmit power from the pedals to the wheel. They were somewhat common a century ago, but were mostly supplanted by chain-driven bicycles. Recently, a small number of modern shaft-driven bicycles have been manufactured and sold. This racing bicycle is built using lightweight, shaped aluminium tubing and carbon fiber stays and forks. ... Cardan driveshaft with universal joints A driveshaft or driving shaft or Cardan shaft is a mechanical device for transferring power from the engine or motor to the point where useful work is applied. ... A bicycle chain is a chain that transfers power from the pedals to the drive-wheel of a bicycle thus propelling it. ...

Shaft-driven bikes have a large bevel gear where a conventional bike would have its chainring. This would mesh to another bevel gear mounted on the driveshaft. The use of bevel gears allows drive from the pedals to be turned through 90 degrees. The driveshaft then has another bevel gear near the rear wheel hub which mesh to a bevel gear on the hub where the rear sprocket would be on a conventional bike. The 90-degree change of plane, for the drive, that occurs at the bottom bracket & again the rear hub requires the use of bevel gears. Bevel gears are notorious to engineers for their lack of efficiency as power is lost to friction. However, bevel gears are more efficient than the alternative methods of turning drive through 90 degrees, like worm gears or crossed helical gears. The driveshaft is often mated to a hub gear adapted from use on chain-driven bikes. The poor efficiency of hub gears could be avoided with the use of a miniaturized version of a car or motorcycle gearbox. However, due to the tiny market share of shaft-driven bikes, & the cost & complexity of the design & manufacture of such a gearbox, there are none in production. Spur gears found on a piece of farm equipment. ... -1... Spur gears found on a piece of farm equipment. ... Cardan driveshaft with universal joints A driveshaft or driving shaft or Cardan shaft is a mechanical device for transferring power from the engine or motor to the point where useful work is applied. ... A square-taper bottom bracket. ... The front wheel from a racing bicycle made using a Mavic rim A bicycle wheel is a wheel designed for a bicycle. ... Worm and worm gear A worm gear, or worm wheel, is a type of gear that engages with a worm to greatly reduce rotational speed, or to allow higher torque to be transmitted. ... Cardan driveshaft with universal joints A driveshaft or driving shaft or Cardan shaft is a mechanical device for transferring power from the engine or motor to the point where useful work is applied. ... Hub gears or internal-gear hubs are a type of gear system used on bicycles. ... Hub gears or internal-gear hubs are a type of gear system used on bicycles. ...

Advantages

• Power loss: Typically, a shaft-driven system would lose less power to friction than a poorly maintained chain-driven system.
• Compactness: The driveshaft & bevel gears takes up less volume than an enclosed chain.
• Ground clearance: As the driveshaft system is more compact it allows greater ground clearance.
• Low maintenance #1: The driveshaft does not need the meticulous cleaning & lubrication regime that a chain does.
• Low maintenance #2: The driveshaft does not need regular adjustment & alignment as a chain or derailleur does.
• Weather protection: The driveshaft & bevel gears are encased & protected from the elements. Even an enclosed chain can still suffer from exposure to rain, mud, dirt & salt.
• Safety #1: There is no danger of clothing or fingers being drawn into the chain & sprockets.
• Safety #2: A shaft-driven bicycle is less likely to suffer from sudden loss of drive. A conventional bike can suffer a broken, falling or slipped chain. This can be particularly dangerous when pedaling "out of the saddle" where a sudden loss of drive can unbalance the rider & potentially cause an accident.
• Durability: A shaft-driven bike would typically be less susceptible to knocks & falls than a conventional bike with its fragile derailleurs & chain.
• Cleanness: As a chain needs to be covered in oil, a conventional bike can stain its rider's clothing & hands.
• Handling ease: The loading onto transportation of a chain-driven bike may spread grease from the chain, cause scrapes from the sprockets or damage the derailleur. Shaft-driven bikes do not suffer from these problems.
• Longevity: Typically the life of a driveshaft should be significantly longer than that of a chain.
• Rough terrain: As rough terrain, jumps & knocks can cause vibration leading to chain slip or fall, a shaft-driven bike may be more suitable in these situations.
• Long cycle suitability: The shaft-driven system is particularly suitable to many recumbent applications where there is a long distance from the pedal the driven rear wheel. Maintaining chain tension is often difficult for these applications. Also, the line of the chain may not be straight straight necessitating the use of extra jockey wheels. A drive shaft can relatively easily turn through these slight angles with the use of a universal joint.

Disadvantages Mountain bicycle with Derailleur gears 9x multiple sprockets of a Derailleur gear Derailleur gears are a gear system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ... Mountain bicycle with Derailleur gears 9x multiple sprockets of a Derailleur gear Derailleur gears are a gear system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ... Mountain bicycle with Derailleur gears 9x multiple sprockets of a Derailleur gear Derailleur gears are a gear system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ... One of two small cogs housed in the lower cage of the rear derailleur (or rear mech) of a bicycle. ... A universal joint, U joint or Cardan joint is a joint in a rigid rod that allows the rod to bend in any direction. ...

• Power loss #1; Typically, a shaft-driven system would lose more power to friction than a well maintained chain-driven system.
• Complexity; Though the shaft-driven system seems simple on the outside, the manufacture of the necessary bevel gears is very complex compared to that of a chain & sprockets.
• Cost; Due to the manufacturing complexity of the shaft-driven system, the cost would typically be higher.
• Choice of gearing; As the chain-driven system has enjoyed market dominance for a century, it has many purpose built gearing systems available for it. As of December 2005, there are no purpose built gearing systems in production for the shaft-driven system. Instead, adapted hub gears from a chain-driven bikes are used.
• Power loss #2; When used with hub gears there is even less efficiency compared to a chain/derailleur system. This is because of the power losses of hub gear systems in production.
• Weight; Overall, a shaft-driven bike would typically have a higher mass than an equivalent chain-driven bike.

Hub gears or internal-gear hubs are a type of gear system used on bicycles. ... Hub gears or internal-gear hubs are a type of gear system used on bicycles. ... Look up chain in Wiktionary, the free dictionary. ... Mountain bicycle with Derailleur gears 9x multiple sprockets of a Derailleur gear Derailleur gears are a gear system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ... Hub gears or internal-gear hubs are a type of gear system used on bicycles. ...

External links

Manufacturer of shaft driven bicycles

Discussion of shaft-driven bicycles

Detailed discussion on gearing