Editing Mountain bike (section)

===Gears===
{{Main|Bicycle gearing}}
Since the 1980s,<ref name="Reinventing">{{cite news|date=1 August 1992|title=Reinventing the wheel|newspaper=The Economist|volume=324|issue=7770|pages=61–62}}</ref><ref name="Ruibal">{{cite news|url=https://www.usatoday.com/sports/cycling/2006-03-22-cycling-bikes_x.htm|title=Still shredding after all these years|last=Ruibal|first=Sal|date=22 March 2006|work=USA Today|access-date=2 December 2010}}</ref> mountain bikes have had anywhere from 7 to 36 speeds, with 1 to 4 chain-rings on the [[crankset]]<ref>{{cite web
|url=http://mgagnon.net/velo/pedalier4.en.php
| title = Installing 4 Chainrings To Climb Almost Anything Without Difficulty
| date = 15 August 2010
| author = Michel Gagnon
| access-date = 15 March 2018}}</ref> and 5 to 12 sprockets in the [[cogset]]. 30-speed, 33-speed and 36-speed mountain bikes were originally found to be unworkable, as the mud-shedding capabilities of a 10-speed, 11-speed or 12-speed cassette, and the intricacies of a 10-speed, 11-speed or 12-speed rear derailleur were originally not found to be suitable combined with front shifters, although 10, 11 and 12 speed cassettes are now commonplace in single front chainring bicycles, and are also found on some mountain bikes. However, many pro-level mountain bikers have taken to using a narrower 10-speed road chain with a 9-speed setup in an effort to reduce the weight of their bike. In early 2009, component group [[SRAM Corporation|SRAM]] announced their release of their XX groupset, which uses a 2-speed front derailleur, and a 10-speed rear derailleur and cassette, similar to that of a road bike. Mud-shedding capabilities of their 10-speed XX cassette are made suitable for MTB use by extensive [[Computer Numerical Control]] (CNC) machining of the cassette. Due to the time and cost involved in such a product, they were only aimed at top-end XC-racers. However, 10-speed has become the norm by 2011 and the market leader [[Shimano]] even offers its budget groupset "Alivio" in a 10-speed version.<ref>{{cite web|url=http://www.bikerumor.com/2011/03/16/bikerumor-chain-challenge-the-definitive-9-vs-10-speed-mtb-chain-wear-test/|title=BikeRumor Chain Challenge: The Definitive 9 VS 10 Speed MTB Chain Wear Test|work=Bikerumor|date=16 March 2011 |access-date=27 August 2015}}</ref> In July 2012, SRAM announced a 1×11 drivetrain called XX1 that does not make use of a front derailleur for lighter weight and simplicity.<ref>{{cite web|url=http://www.bikeradar.com/mtb/news/article/sram-xx1-set-for-release-in-october-2012-34457/|title=SRAM XX1 set for release in October 2012|author=BikeRadar UK|work=BikeRadar|access-date=27 August 2015}}</ref> In the 2014 Commonwealth Games at Glasgow all leading riders used 1×11 drivetrains. SRAM's new 1×12 gearing was introduced in 2016 as SRAM Eagle. This gives a single chain ring bike better ability to climb.