A few decades back, 26” wheels were used on mountain bikes. The mountain bikes having 26” wheels are still demanded but larger 29” wheels have also become popular. So, the bike shop owners will certainly ask about your preferred wheel size if you step inside their shop for purchasing mountain bikes.
29 inch (“29ers”)
The 29” wheels significantly increase the weight of your bike with additional rim and rubber. The heavier wheels can be a bit slower during the initial acceleration, but provide greater momentum once they start rolling. The larger wheels increase the grip and the attack angle of the mountain bikes so that you can effortlessly pass through obstacles with minimum chances of sliding or skidding.
Tip: The mountain bikes with 29” wheels can be used by any rider, but they are specifically suitable for taller riders or when it has to be used on both pavement and mountain trails.
Note: You must understand that some components are not interchangeable between 26 and 29-inch wheel sized bikes, and increased wheel frame size requires totally different frame and suspension.
The kid’s legs are shorter and therefore, 24 inch shorter wheels are used on their mountain bikes. The mountain bikes equipped with 24” wheels are cost-effective variants of normal bikes. The components of bikes are quite simple as children in age groups of 10-13 years are not supposed to perform complicated maneuvering. However, the choice of wheel size depends on the height of the kids rather than age. The 20” wheel option is also available to support the learning phase of small children.