What is the name of the wheel component that the tire sits on? The component is the rim.
A bicycle rim is the outer circular hoop of a wheel. It connects to the hub through spokes and provides the structure on which the tire is mounted. In a conventional clincher setup, the tire’s bead fits against shaped flanges or hooks in the rim, while an inner tube holds air and presses the bead securely into place. Tubeless systems seal directly between the tire and rim without an inner tube.
The rim is not the same as the hub, spoke, or spindle. The hub is the central rotating body around the axle; spokes connect that hub to the rim; and a spindle or axle supports rotation. Together, these parts form the wheel, but only the rim is the tire’s mounting hoop.
Rim design affects a bicycle’s weight, strength, handling, and tire compatibility. Width influences the shape of the tire and its contact patch, while diameter must match the tire’s bead-seat diameter. Tubular tires are a useful exception to ordinary clinchers: they are glued or otherwise attached to a specially shaped tubular rim rather than held by clincher sidewalls and flanges.