Huffy Mountain Bike 24 In Wheel Bikes For Sale Trek’s Smart Wheel Size approach pairs 29” wheels with M, L, and XL frames and places 27.5” wheels on XS and S frame sizes. The major wheel sizes available on mountain bikes are 26”, 27.5” and 29”. Choosing the right wheel diameter for you'll be able to help narrow down your search and assist you to discover the proper bike to swimsuit your needs. Stack is the vertical distance between the bottom bracket and the center of the top tube and determines how a motorbike will really feel whereas pedaling in the saddle. While nonetheless an necessary metric to consider, stack doesn’t change as much as reach does between body sizes. The slightly shorter wheelbase provides a extra nimble and zippy ride feel.