
A 29er single speed refers to a bicycle that has 29 inch wheels, or 700C wheel set as well as only one speed. There are no front and rear derailleur’s and no extra gears for them to switch to. The chain is tensioned and may or may not have a free wheel, i.e. the rear wheel can either spin freely when not pedaling or there is a direct connection to the pedals.
When a 29er single speed does not have a free spinning rear wheel the pedals will always spin when the wheel is in motion whether it is forward or reverse. Often these will not have any brakes forcing the rider to use their legs to slow the bike in time. A bike with a free wheel will require at least coaster brakes to stop but calipers are more common.
The unique thing about a 29er single speed bicycle is the size of the wheel. Most wheels are only 26 inches. A 29 inch wheel allows the rider to get over larger obstacles, gives them more top speed and is ideal for larger riders although they are popular among riders of all sizes. They are more difficult to get up to speed and can make climbing steep hills almost impossible, but they have a large base of riders that swear by them.