29er (bicycle)
29ers or Two-niners are mountain bicyles that are built to use 700c or ISO 622mm rims. Most mountain bicycles use ISO 559mm rims which are commonly called 26" rims. The ISO 622mm rim is typically also used for road-racing, trekking, cyclocross, touring and hybrid bicycles. The term 29er can also refer to a type of skiff.
Origin of 29ers
The term 29er of two-niner is a little misleading. The rims have a diameter of approximately 24.5" (622mm) and the average 29" mountain bike tire has an outside diameter of about 28.5" (724mm). The typically 26er rim has a diameter of 22.0" (559mm) and an outside tire diameter of about 26.2" (665mm)
The differences between a 29er bicycle and a cyclocross bicycle can sometimes be fuzzy. Typically any tire with a tread width of less than 2.0" (50 mm) is considered a cyclocross tire. Cyclocross and 29ers typically differ in other ways, but some riders use one for both types of riding. However, there are generally limitations since most cyclocross bikes are more of a challenge to handle offroad on technical trails, and 29ers have their weaknesses in cyclocross mode being heavier and harder to shoulder.
Many manufactures are viewed as early or current supporters of the 29er movement. A sense of pride at being one of the first to adopt or support the change seems prevalent. Various people claim or are attributed to be the originator of the term 29er, some of the most plausible being Wes Williams of Crested Butte, CO and Brian Crocco of Auburn, NY. An early proponent of 29er mountain bikes was Bianchi with their Project X bikes. The Project X bikes were not a marketing success due to many reasons. Some being consumer attitude, some being a lack of acceptable tires and suspensions forks.
Other early supporters of the 29er movement were Wilderness Trail Bikes (WTB), Willy’s Bicycles, and Independent Fabrication. Currently Gary Fisher bicycles is the strongest major bike manufacturer in the US market that supports 29ers. A new compnay, Niner Bikes, is the first to only produce mountian bikes in the 29er format. The trend seems to predict more major manufactures will begin developing and marketing mountain bikes with 29” wheels.
Performance Drawbacks and Advantages
A debate over the advantages and disadvantages is currently raging in the mountain bike community. Different bike experts seriously state that some of the characteristics of 29ers are disadvantages while other claim those same characteristics are advantages. The best example of such a characteristic is the greater mass of the wheels and tires. 29er detractors point out the greater mass retards acceleration, while promoters claim the small increase in rotational mass leads to smoother speeds over rough terrain.
Drawbacks
- Larger wheels increases the overall wheelbase and size of the bicycle, possibly retarding handling in tight terrain
- Increased weight
Advantages
- Larger wheels roll over larger obstacles
- Larger wheels have a lower rolling resistance for the same width tire
- Larger wheels are less prone to sinking in soft material
- Larger wheels may be less prone to pinch flatting
Some riders of 29”er spend lots of time raving about their advantages hoping to convince more riders to switch from 26” MTBs. This can be attributed to both altruistic ideals and hoping to increase to market presence of 29”er items. The 29”er market still suffers from narrow choices of frame designs, suspension forks, tires and wheels that can only be solved by offering larger market to manufactures.
The debates regarding 29”ers can be viewed at many places, especially on-line forums such as those on Dirt Rag Mag and Mountain Bike Review.
Disparaging References
Friendly jibes are often exchanged between those riding 26” and 29” wheels mountain bicycles. Cyclists that choose to ride 29er mountain bikes insultingly refer to 26" wheel mountain bikes as baby-wheeled, kiddie wheels or BMX bikes. Those riding 26" mountain bikes refer to 29er bikes as hybrids, quasi-roadies or cross bikes.