"mountain bike." YourDictionary, n.d. Web. 14 January 2019. <https://www.yourdictionary.com/mountain-bike>.
mountain bike. (n.d.). Retrieved January 14th, 2019, from https://www.yourdictionary.com/mountain-bike
(plural mountain bikes)
A bicycle specially designed for off-road riding, typically with straight, flat handlebars, a heavier frame than road bikes, higher ground clearance, and wider tires, sometimes with knobs on them for greater traction.
English Wiktionary. Available under CC-BY-SA license.