29er (bicycle)

29ers or two-niners are mountain bikes and hybrid bikes that are built to use 700c or 622 mm ISO (inside rim diameter) wheels, commonly called 29″ wheels.^[1] Most mountain bikes once used ISO 559 mm wheels, commonly called 26″ wheels. The ISO 622 mm wheel is typically also used for road-racing, trekking, cyclo-cross, touring and hybrid bicycles. In some countries, mainly in Continental Europe, ISO 622 mm wheels are commonly called 28″ wheels or "28 Incher".^[2]

^ "29er Mountain Bikes – All you ever wanted to know about 29 inch wheeled bicycles". ConsumerREVIEW.com. Archived from the original on 2012-02-24. Retrieved 2012-09-08. 29ers are mountain bikes built around 700c sized wheels resulting in an outside tire diameter of about 29 inches
^ Sheldon Brown (April 18, 2012). "Tire Sizing Systems". Retrieved 2012-09-08. Unfortunately, evolution of tires and rims has made these measurements lose contact with reality. Here's how it works: Let's start with the 26 × 2.125 size that became popular on heavyweight "balloon tire" bikes in the late 30s and still remains common on "beach cruiser" bikes. This size tire is very close to 26 inches in actual diameter. Some riders, however were dissatisfied with these tires, and wanted something a bit lighter and faster. The industry responded by making "middleweight" tires, marked 26 × 1.75 to fit the same rims. Although they are still called "26 inch", these tires are actually 25 5/8″, not 26″. This same rim size was adopted by the early pioneers of west-coast "klunkers", and became the standard for mountain bikes. Due to the appetite of the market, you can get tires as narrow as 25 mm to fit these rims, so you wind up with a "26 inch" tire that is more like 24 7/8″ in actual diameter!

[mtbr-1] "29er Mountain Bikes – All you ever wanted to know about 29 inch wheeled bicycles". ConsumerREVIEW.com. Archived from the original on 2012-02-24. Retrieved 2012-09-08. 29ers are mountain bikes built around 700c sized wheels resulting in an outside tire diameter of about 29 inches

[Brown-2] Sheldon Brown (April 18, 2012). "Tire Sizing Systems". Retrieved 2012-09-08. Unfortunately, evolution of tires and rims has made these measurements lose contact with reality. Here's how it works: Let's start with the 26 × 2.125 size that became popular on heavyweight "balloon tire" bikes in the late 30s and still remains common on "beach cruiser" bikes. This size tire is very close to 26 inches in actual diameter. Some riders, however were dissatisfied with these tires, and wanted something a bit lighter and faster. The industry responded by making "middleweight" tires, marked 26 × 1.75 to fit the same rims. Although they are still called "26 inch", these tires are actually 25 5/8″, not 26″. This same rim size was adopted by the early pioneers of west-coast "klunkers", and became the standard for mountain bikes. Due to the appetite of the market, you can get tires as narrow as 25 mm to fit these rims, so you wind up with a "26 inch" tire that is more like 24 7/8″ in actual diameter!

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