Gearbox bicycle
File:Instinctiv gearbox mountain bike.jpg
A gearbox bicycle is a bicycle that uses a gearbox{{cite magazine
| url = http://www.bikemag.com/gear/bikes/preview-nicolai-bikes-now-available-us/
| title = Preview: Nicolai Bikes Available in the U.S.
| author = Dylan H. Brown
| date = June 3, 2014
| magazine=Bike
| quote = Nicolai's gearbox bikes have also been popular.
| access-date = 2015-03-22}}{{cite web
| url = http://www.vitalmtb.com/photos/features/Zerodes-Full-Carbon-Gearbox-Trail-Bike,7113/Slideshow,0/sspomer,2
| title = Zerode's Prototype Full Carbon 27.5 Gearbox Trail Bike
| author = Sven Martin
| date = February 17, 2014
| publisher = VitalMTB
| quote = Zerode founder, Rob Metz, built this incredible prototype carbon gearbox trail bike in his garage.
| access-date = 2015-03-22}} 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.{{cite web
| url = https://eandt.theiet.org/content/articles/2015/02/bicycle-gearbox-project-shifts-to-top-speed-with-cnc-prototyping/
| title = Bicycle gearbox project shifts to top speed with CNC prototyping
| author = Bryan Betts
| date = February 18, 2015
| quote = The Efneo gearbox packs a three-speed planetary design into the same volume as the triple-chainring it replaces.
| publisher = The Institute of Engineering and Technology
| access-date = 2015-03-22}} Cited advantages include improved shifting performance,{{cite web
| url = http://www.gizmag.com/efneo-front-gearbox/34155/
| title = Efneo gearbox is made to replace a bike's front derailleur
| author = Ben Coxworth
| date = October 7, 2014
| publisher = GizMag
| access-date = 2015-03-22}} protecting the gearing from damage and exposure to dirt and moisture,{{cite web
| url = http://www.gizmag.com/nuseti-inner-drive-system-mountain-bike/32914/
| title = Nuseti mountain bike features a sealed drivetrain
| author = Ben Coxworth
| date = July 10, 2014
| publisher = GizMag
| quote = Both the gearbox and the chain are sealed against water and outside contaminants, plus they're kept lubricated by separate sealed-in oil baths. This means that riders won't be exposed to greasy crud, and won't need to frequently clean or lube the drivetrain.
| access-date = 2015-03-22}} as with hub gears, plus locating the additional mass between the two wheels and on the frame where it may be suspended,{{cite magazine
| url = http://www.bikemag.com/events/german-gearbox-makes-nahbs-splash-reeb-mountain-bike/
| title = German Gearbox Makes An NAHBS Splash On Reeb Mountain Bike
| author = Robert Annis
| date = March 16, 2014
| magazine=Bike
| quote = They toyed with the idea of an internal rear hub, but didn't like the idea of adding additional weight to the rear of the bike.
| access-date = 2015-03-22}} unlike with hub gears.{{cite web
| url = http://www.gizmag.com/pinion-p118-sealed-gearbox/26640/
| title = Pinion sealed gearbox offers an alternative to those darn derailleurs
| author = Ben Coxworth
| date = March 13, 2013
| publisher = GizMag
| quote = [Hub gears] add revolving weight, and that weight is added in the back of the bike – not low and in the middle, where you want it.
| access-date = 2015-03-22}}
History
Patents for built-in systems to change gear ratios appeared as early as 1890.
{{cite book
|author=Berto, Frank J.
|title=The Dancing Chain: History and Development of the Derailleur Bicycle
|edition=3rd
|year = 2008
|orig-date=2000
|publisher = Cycle Publishing/Van der Plas Publications
|isbn = 978-1-892495-59-4
|pages = 39–47
{{cite book
|author=Berto, Frank J.
|title=The Dancing Chain: History and Development of the Derailleur Bicycle
|edition=5th
|year=2016
|orig-date=2000
|publisher=Cycle Publishing/Van der Plas Publications
|isbn=978-1-892495-77-8
|url=http://www.cyclepublishing.com/cyclingbooks/
|access-date=May 30, 2017
}} Adler offered a three-speed gearbox bicycle in the 1930s.{{cite web
| url = http://www.oldbike.eu/museum/1930s/1936-2/1936-adler-drei-gang-typ-155/
| title = 1936 Adler Drei-Gang Typ 155
| publisher = The Online Bicycle Museum
| quote = With its automobile-style gear-stick, the Adler Drie-Gang (it means '3-Speed') has a most distinctive appearance. It was Germany's best-selling bottom-bracket-geared bicycle.
| access-date = 2015-03-22
| archive-date = 2015-03-09
| archive-url = https://web.archive.org/web/20150309162247/http://www.oldbike.eu/museum/1930s/1936-2/1936-adler-drei-gang-typ-155/
| url-status = dead
}} Several attempts to develop gearbox bicycles during the 2000s for downhill racing, such as the Honda RN-01 G-cross, incorporated complete derailleur gear drive trains in an enclosure.
{{cite web
| url = http://mbaction.com/product-tests/hayes-to-market-chain-driven-gearbox-system-oct-5
| title = Hayes to Market Chain-Driven Gearbox System
| author = Richard Cunningham
| date = October 5, 2004
| publisher = Mountain Bike Action
| quote = The PeteSpeed patented gearbox is actually a small derailleur that is packed into machined-aluminum housing, mounted in the frame near the bottom bracket area.
| access-date = 2015-03-22
| url = http://www.bikeradar.com/us/news/article/honda-gearbox-revealed-12941/
| title = Honda gearbox revealed
| author = Jez Loftus
| date = October 23, 2007
| publisher = BikeRadar
| quote = The system basically {{sic|comprises|hide=y}} of a drive crank, chained through what looks to be a reworked derailleur running onto a regular cassette.
| access-date = 2015-03-22
| archive-date = 2015-04-02
| archive-url = https://web.archive.org/web/20150402111818/http://www.bikeradar.com/us/news/article/honda-gearbox-revealed-12941/
| url-status = dead
}} Around the same time Schlumpf Innovations and Hammerschmidt offered cranksets with two different gear ratios and just one chainring.{{cite web
| url = http://www.bikemag.com/news/freshproduce/8-12-08-previewed-unveiling-truvativs-hammerschmidt/
| title = Previewed: Unveiling Truvativ's Hammerschmidt
| publisher = bikemagazine
| last = Davis
| first = Alan
| date = August 13, 2008
{{cite web
|url=http://www.schlumpf.ch/
|title=Schlumpf Innovations
|access-date=2010-05-05
Methods
At least three different gearing techniques have been employed.
- Epicyclic gears, as in hub gears.
- Spur gears, as in most automobile transmissions.
- Derailleur gears, as on many bicycles, but fully enclosed.
See also
Gallery
File:Pinion P1.18 interior.jpg|Pinion P1.18 gearbox interior
File:Schlumpf Speed Drive bottom bracket.JPG|Schlumpf Speed Drive
File:Britannica Bicycle Sunbeam Two-Speed Gear.jpg|Diagram of the Sunbeam two-speed gear for a bicycle (part of the crank) assembly from the 1911 Encyclopædia Britannica, Vol. 3, p. 916
File:L-Variand.png|Image from the Lexikon der gesamten Technik (dictionary of technology) from 1904 by Otto Lueger
File:Adler geared bottom bracket 1936.jpg|Adler gearbox with 3 gears from 1936
File:Motaped2.jpg|Mutaped gearbox external view
File:Mutaped.jpg|Mutaped gearbox internal view