Search results
Results from the WOW.Com Content Network
Multiple speed freewheels were common on quality high end bikes until the late 1980s. [3] Suntour — Maeda Industries (Japan) introduced a compact 6 speed freewheel which reduced the spacing between the sprockets and was the same width as a standard 5 speed freewheel but required a narrower chain than the standard.
Major changes in bicycle form have often been initiated or accompanied by advances in drivetrain systems. Several early drivetrains used straight-cut gears that meshed directly with each other outside of the hub. [1] [2] Some bicycles have used a double-sided rear wheel, with different-sized sprockets on each side. To change gears, the rider ...
Single-speed mountain bike. A single-speed bicycle is a type of bicycle with a single gear ratio and a freewheel mechanism. These bicycles are without derailleur gears, hub gearing or other methods for varying the gear ratio of the bicycle. Adult single-speed bicycles typically have a gear ratio of between 55 and 75 gear inches, depending on ...
The front derailleur, however, switches gears almost 30% faster than Dura-Ace’s mechanical counterpart. [1] On traditional bikes, the front derailleur is problematic because the chain can be under tension and has to make a large vertical jump between chainrings. The electronic system's controlled motion overcomes these problems.
From a mechanical viewpoint, up to 99% of the mechanical energy delivered by the rider into the pedals is transmitted to the wheels (clean, lubricated new chain at 400 W), although the use of gearing mechanisms reduces this by 1–7% (clean, well-lubricated derailleurs and a straight chainline), 4–12% (chain with 3-speed hubs), or 10–20% (shaft drive with 3-speed hubs).
The only application currently commercialized is the internally geared bicycle hub. The NuVinci CVT replaces derailleurs and other internally geared hubs, and provides a gear ratio range of about 350%, similar to that on bicycles with 8- or 9-speed hub gears, or with double chain rings (most racing or fast road bicycles). [12]
Before epicyclic gears were used in bicycle hubs, they were used on tricycles. Patents for epicyclic hubs date from the mid-1880s. [5] [6] The first patent for a compact epicyclic hub gear was granted in 1895 to the American machinist Seward Thomas Johnson of Noblesville, Indiana, U.S.A. [7] This was a 2-speed but was not commercially successful.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us