These innovations have continued with the advent of modern materials and computer-aided design, allowing for a proliferation of specialized bicycle types.
Less common are tandems, lowriders, tall bikes, fixed gear, folding models and recumbents (one of which was used to set the IHPVA Hour record).
Unicycles, tricycles and quadracycles are not strictly bicycles, as they have respectively one, three and four wheels, but are often referred to informally as "bikes".
More recently, bicycle technology has in turn contributed ideas in both old and new areas.
The International Organization for Standardization, ISO, has a special technical committee for cycles, TC149, that has the following scope: "Standardization in the field of cycles, their components and accessories with particular reference to terminology, testing methods and requirements for performance and safety, and interchangeability."
This
mountain bicycle
features oversized tires, a full-suspension frame, two disc brakes and handlebars oriented perpendicular to the bike's axis.
Touring bicycle equipped with
head lamp
,
pump
, rear
rack
, fenders/mud-guards, water bottles and
cages
, and numerous pannier bags
Puncture repair kit with tire levers, sandpaper to clean off an area of the inner tube around the puncture, a tube of rubber solution (vulcanizing fluid), round and oval patches, a metal grater and piece of chalk to make chalk powder (to dust over excess rubber solution). Kits often also include a wax crayon to mark the puncture location.
