Wheel spokes meet. A hubless wheel (also known as a rim-rider or centerless wheel) is a type of wheel with no center hub. More specifically, the hub is actually almost as big as the wheel itself. The axle is hollow, following the wheel at very close tolerances. A spoke is one of some number of rods radiating from the center of a wheel (the hub where the axle connects), connecting the hub with the round traction surface. The term originally referred to portions of a log which had been split lengthwise into four or six sections. The radial members of a
Flip-flop hub Flip-flop hub Flip-flop hubs, also called double-sided hubs, are rear bicycle hubs that are threaded to accept fixed cogs and/or freewheels on both sides. There are several different types of flip flop hubs available for different applications. Their main purpose is to allow changing between two different size gear ratios on one rear wheel without the added complications of a derailleur or internal hub gear, or between a fixed and freewheeling option. By removing the rear wheel and flipping it around, the rider can switch between the two options. They are traditionally found on track bicycles, but can also be