Editing Cross-country skiing (section)

==Equipment==
[[File:108 Frognersæteren - no-nb digifoto 20150914 00046 bldsa PK02744.jpg|thumb|Pre-1940 ski gear in Oslo: bamboo poles, wooden skis, and [[cable binding]]s.]]
Equipment comprises skis, poles, boots and bindings; these vary according to:
* Technique, classic vs skate
* Terrain, which may vary from groomed trails to wilderness
* Performance level, from recreational use to competition at the elite level<ref name="Rees"/>

===Skis===
{{main article|Ski}}
[[File:Cross-country equipment--Skate and Classic.jpg|thumb|Cross-country ski equipment for skate-skiing (left) and classic-style skiing (right). Ski and pole lengths are different for each. Classic skis have a "grip zone" in the area under the binding.]]
Skis used in cross-country are lighter and narrower than those used in [[alpine skiing]]. Ski bottoms are designed to provide a gliding surface and, for classic skis, a traction zone under foot. The base of the gliding surface is a plastic material that is designed both to minimize friction and, in many cases, to accept waxes.<ref name=oly>{{cite web|title=Cross Country Skiing Equipment and History|url=http://www.olympic.org/cross-country-skiing-equipment-and-history?tab=history|publisher=International Olympic Committee|access-date=2014-10-11|archive-date=16 October 2014|archive-url=https://web.archive.org/web/20141016185653/http://www.olympic.org/cross-country-skiing-equipment-and-history?tab=history|url-status=live}}</ref> Glide wax may be used on the tails and tips of classic skis and across the length of skate skis.<ref name="Rees"/><ref name=mec>{{cite web|title=Cross Country Skis (Nordic Skis)|url=http://www.mec.ca/AST/ContentPrimary/Learn/Snowsports/SkisBootsAndSkins/NordicSkis.jsp|website=MEC|publisher=Mountain Equipment Coop|access-date=2014-10-19|archive-date=13 August 2012|archive-url=https://web.archive.org/web/20120813113907/http://www.mec.ca/AST/ContentPrimary/Learn/Snowsports/SkisBootsAndSkins/NordicSkis.jsp|url-status=live}}</ref>

====Types====
Each type of ski is sized and designed differently. Length affects maneuverability; camber affects pressure on the snow beneath the feet of the skier; side-cut affects the ease of turning; width affects forward friction; overall area on the snow affects bearing capacity; and tip geometry affects the ability to penetrate new snow or to stay in a track.<ref name = SnowCountry>{{Citation
 | last = Woodward
 | first = Bob
 | title = Cross Country's Short Story
 | journal = Snow Country
 | volume = 8
 | issue = 1
 | pages = 127–132
 | date = January 1995
 | url = https://books.google.com/books?id=rEEo8WqmRRsC&q=Cross-country+ski+design&pg=PA127
 | access-date = 2016-01-05
 | issn = 0896-758X
 | archive-date = 6 May 2016
 | archive-url = https://web.archive.org/web/20160506044107/https://books.google.com/books?id=rEEo8WqmRRsC&pg=PA127&dq=Cross-country+ski+design&hl=en&sa=X&ved=0ahUKEwir44ns15PKAhVChhoKHdIWC4kQ6AEIRzAJ#v=onepage&q=Cross-country%20ski%20design&f=false
 | url-status = live
 }}</ref> Each of the following ski types has a different combination of these attributes:
* '''Classic skis''': Designed for skiing in tracks. For adult skiers (between 155&nbsp;cm/50&nbsp;kg and 185&nbsp;cm/75&nbsp;kg), recommended lengths are between 180 and 210 centimetres (approximately 115% of the skier's height). Traction comes from a "grip zone" underfoot that when bearing the skier's weight engages either a textured gripping surface or a grip wax. Accordingly, these skis are classified as "waxable" or "waxless". Recreational waxless skis generally require little attention and are adapted for casual use. Waxable skis, if prepared correctly, provide better grip and glide.<ref name="Rees"/><ref name="Bergin">{{cite web|url = http://www.snocountry.com/article.php/20041227133240622 |title = Back to Basics: A Quick Look at Paste Waxes, Waxless Ski Preparation and Kick Waxing|access-date = 2009-01-25|last = Bergin|first = Ron |year = 2008 |archive-url = https://web.archive.org/web/20070402051820/http://www.snocountry.com/article.php/20041227133240622 |archive-date = 2 April 2007}}</ref><ref name="REIAdvice">{{cite web|url = http://www.rei.com/learn/expert-advice/crosscountry-ski-touring-gear.html|title = Cross-Country Ski Gear: How to Choose|access-date = 2015-06-29|last = Recreational Equipment, Inc.|year = 2015|archive-date = 16 May 2015|archive-url = https://web.archive.org/web/20150516163933/http://www.rei.com/learn/expert-advice/crosscountry-ski-touring-gear.html|url-status = live}}</ref>

:When the skier's weight is distributed on both skis, the ski's [[wikt:camber|camber]] diminishes the pressure of the grip zone on the snow and promotes bearing on the remaining area of the ski—the "glide zone". A test for stiffness of camber is made with a piece of paper under the skier's foot, standing on skis on a flat, hard surface—the paper should be pinned throughout the grip zone of the ski on which all the skier's weight is placed, but slide freely when the skier's weight is bearing equally on both skis.<ref name = Mountaineers/>
* '''Skate skis''': Designed for skiing on groomed surfaces. The usual recommended length is skier length +5-15cm.  The entire bottom of each skate ski is a glide zone—prepared for maximum glide. Traction comes from the skier pushing away from the edge of the previous ski onto the next ski.<ref name="Rees"/>
* '''Back country skis''': Designed for [[ski touring]] on natural snow conditions. Recommended lengths are between 150 and 195 centimeters for adult skiers, depending on height and weight of the user. Back country skis are typically heavier and wider than classic and skate skis; they often have metal edges for better grip on hard snow; and their greater [[sidecut]] helps to carve turns.<ref name=Berg/><ref>{{cite web| title = How to choose the right ski length | work = Back Country | date = 2 September 2013 | url = http://www.backcountry.com/explore/how-to-pick-the-right-ski-length | access-date = 2014-10-22 | archive-date = 23 October 2014 | archive-url = https://web.archive.org/web/20141023055824/http://www.backcountry.com/explore/how-to-pick-the-right-ski-length | url-status = live }}</ref><ref name=Melbye/>

:The geometry of a back country ski depends on its purpose—skis suited for forested areas where loose powder can predominate may be shorter and wider than those selected for open, exposed areas where compacted snow may prevail. Sidecut on Telemark skis promotes turning in forest and rugged terrain. Width and short length aid turning in loose and deep snow. Longer, narrower and more rigid skis with sharp edges are suited for snow that has been compacted by wind or freeze-thaw. Touring ski design may represent a general-purpose compromise among these different ski conditions, plus being acceptable for use in groomed tracks.<!---We don't see these terms in English: (referred to as mountain skis or crust skis)---> Traction may come from a textured or waxed grip zone, as with classic skis, or from [[ski skins]], which are applied to the ski bottom for long, steep ascents and have hairs or mechanical texture that prevents sliding backwards.<ref name=Berg/><ref name=Melbye>{{cite book|last1=Melbye|first1=Mats|title=Friluftsliv i vinterfjellet|date=1997|publisher=Universitetsforlaget|location=Oslo|isbn=82-00-42088-4|pages=31–32}}</ref>

====Gliding surface====
{{main article|Ski wax#Glide wax}}
Glide waxes enhance the speed of the gliding surface. The wax is either melted on the base using an iron or applied in a liquid form. The excess wax is first scraped off and then finished by brushing. Most glide waxes are based on [[Paraffin wax|paraffin]] that is combined with additive materials. The paraffin hardness and additives are varied based on snow type, humidity and temperature. Since the 2021-2022 race season, fluorinated products are banned in FIS sanctioned competitions.<ref>{{Cite web|title=Flourinated Wax Ban implementation to begin in the 2021-22 season|url=https://www.fis-ski.com/en/international-ski-federation/news-multimedia/news/flourinated-wax-ban-implementation-to-begin-in-the-2021-22-season|access-date=2021-11-05|website=www.fis-ski.com|language=en}}</ref> Before the ban, most race waxes combined fluorinated hydrocarbon waxes with [[fluorocarbon]] overlays.<ref>{{cite web |last=Harvey |first=Ian |date=9 February 2011 |title=Information on Fluorinated Waxes |url=http://www.nordicskiracer.com/news.asp?NewsID=5429 |url-status=live |archive-url=https://web.archive.org/web/20120425075240/http://www.nordicskiracer.com/news.asp?NewsID=5429 |archive-date=25 April 2012 |access-date=2014-10-21 |work=A Michigan Nordic Ski Racer}}</ref> Fluorocarbons decrease surface tension and surface area of the water between the ski and the snow, increasing speed and glide of the ski under specific conditions. Either combined with the wax or applied after in a spray, powder, or block form, fluorocarbons significantly improve the glide of the ski.<ref>{{cite web |last=Swix |date=22 February 2011 |title=Information on Fluorinated Waxes |url=http://www.nordicskiracer.com/news.asp?NewsID=5482 |url-status=live |archive-url=https://web.archive.org/web/20120425080020/http://www.nordicskiracer.com/news.asp?NewsID=5482 |archive-date=25 April 2012 |access-date=2014-10-21 |work=A Michigan Nordic Ski Racer}}</ref>

====Traction surface====
{{main article|Ski wax#Grip wax}}
Skis designed for classic technique, both in track and in virgin snow, rely on a traction zone, called the "grip zone" or "kick zone", underfoot. This comes either from a) ''texture'', such as "[[fish scale]]s" or [[mohair]] skins,<ref>{{Cite web|last=Jhung|first=Lisa|date=2020-12-05|title=This Is the Winter to Invest in Cross-Country Skis|url=https://www.outsideonline.com/2419169/how-buy-cross-country-skis|access-date=2021-03-02|website=Outside Online|language=en}}</ref> designed to slide forward but not backwards, that is built into the grip zone of waxless skis, or from applied devices, e.g. [[Ski skins|climbing skins]], or b) from ''grip waxes''. [[Ski wax#Grip wax|Grip waxes]] are classified according to their hardness: harder waxes are for colder and newer snow. An incorrect choice of grip wax for the snow conditions encountered may cause ski slippage (wax too hard for the conditions) or snow sticking to the grip zone (wax too soft for the conditions).<ref name="Rees"/> Grip waxes generate grip by interacting with snow crystals, which vary with temperature, age and compaction.<ref name="Rees"/> Hard grip waxes do not work well for snow which has metamorphosed to having coarse grains, whether icy or wet. In these conditions, skiers opt for a stickier substance, called ''klister''.<ref name="Rees"/>

===Boots and bindings===
[[File:Cross-country ski boot and binding system--Classic.jpg|thumb|Cross-country ski boot and ''standardized'' binding system for classic skiing. The skier clicks the toe of the boot into the binding and releases with the button in front of the boot.]]
[[Ski boots]] are attached to the ski only at the toe, leaving the heel free. Depending on application, boots may be lightweight (performance skiing) or heavier and more supportive (back-country skiing).<ref name=Boot-binding/>

[[Ski binding|Bindings]] connect the boot to the ski. There are three primary groups of [[Nordic Integrated System|binding systems]] used in cross-country skiing (in descending order of importance):<ref name=Boot-binding>{{cite web | last = Dzierzak | first = Lou | title = Cross country skiers venture off track | department = On the Wild Side | work = Cross Country Skier Magazine | date = November 2008 | url = http://www.crosscountryskier.com/magazine/08_nov/wild_side.htm | access-date = 2014-10-21 | url-status = dead | archive-url = https://web.archive.org/web/20150302164504/http://www.crosscountryskier.com/magazine/08_nov/wild_side.htm | archive-date = 2 March 2015}}</ref>
* '''Standardized system''': Boots and bindings have an integrated connection, typically a bar across the front end of the sole of the boot, and platform on which the boot rests. Two families of standards prevail: NNN (New Nordic Norm) and SNS (Salomon Nordic System) Profil. Both systems have variants for skiing on groomed surfaces and in back country. These systems are the most common type of binding.
* '''Three-pin''': The boot-gripping system comprises three pins that correspond to three holes in the sole of the boot's toe, used primarily for back-country skiing.
* '''Cable''': A [[Cable binding|cable]] secures the free-moving heel and keeps the toe of the boot pushed into a boot-gripping section, used primarily for back-country and telemark skiing.

===Poles===
{{main article|Ski pole}}
Ski poles are used for balance and propulsion. Modern cross-country ski poles are made from [[aluminium]], [[fibreglass-reinforced plastic]], or [[carbon fibre]], depending on weight, cost and performance parameters. Formerly they were made of wood or [[bamboo]].  They feature a foot (called a basket) near the end of the shaft that provides a pushing platform, as it makes contact with the snow. Baskets vary in size, according to the expected softness/firmness of the snow. Racing poles feature smaller, lighter baskets than recreational poles. Poles designed for skating are longer than those designed for classic skiing.<ref name=pole>{{cite web | last = Hindman | first = Steve | title = Poling Principles | department = Training & Technique | work = Cross Country Skier | date = February 2004 | url = http://www.crosscountryskier.com/training_technique_feb_2004.html | access-date = 2014-11-18 | url-status = dead | archive-url = https://web.archive.org/web/20141129024911/http://www.crosscountryskier.com/training_technique_feb_2004.html | archive-date = 29 November 2014}}</ref> Traditional skiing in the 1800s used a single pole for both cross-country and downhill. The single pole was longer and stronger than the poles that are used in pairs. In competitive cross-country poles in pairs were introduced around 1900.<ref name= Aftenposten>{{cite news
 | last = Brugge
 | first = Mette
 | title = Skistavens historie: Hjelpemiddel og bråkmaker
 | newspaper = [[Aftenposten]]
 | location = Oslo
 | pages = 14
 | language = no
 | date = 20 December 2015
 | url = http://www.aftenposten.no/fakta/innsikt/Skistavens-historie-Hjelpemiddel-og-brakmaker-8288452.html
 | access-date = 2015-12-22
 | archive-date = 23 December 2015
 | archive-url = https://web.archive.org/web/20151223141051/http://www.aftenposten.no/fakta/innsikt/Skistavens-historie-Hjelpemiddel-og-brakmaker-8288452.html
 | url-status = live
 }}</ref>