What Is Rim Tape?

Rim tape is a circular strip of plastic or textile material that is used to protect bicycle inner tubes from spoke punctures. The rim tape is installed along the circumference of the rim such that it acts as a barrier between the rim and inner tube. To fully understand the function of rim tape, it helps to understand the anatomy of a bicycle wheel.

  1. Hubs

    • The hub is located at the center of each wheel. Through the center of each hub is a threaded axle which allows each wheel to be mounted onto the bicycle frame or fork. Inside the hub, encircling the axle, are two sets of bearings. These bearings allow the entire wheel to spin freely on the axle, which allows the bicycle to roll. The metal casing that encloses the axle, bearings and other hardware is the hub shell.

    Spokes

    • On each edge of the hub are flanges with circular eyelets through which the spokes are installed. Spokes are thin metal rods with a hooked flange on one end and a threaded tip on the other end. Each spoke flange hooks into an individual eyelet on the hub flange. The threaded end of the spoke is secured into the rim. To increase the strength of the wheel, spokes are cross-laced such that, when tightened, the entire system of spokes connects the hub to the rim in a sturdy structure.

    Rims

    • A rim is the outer metal ring that defines the overall size of the wheel. On the inner diameter of the rim are eyelets through which the threaded end of the spokes protrude. Threaded spoke heads, or nipples, are secured onto each threaded spoke end from the reverse side of the rim. This keeps the spokes in place and applies tension so the wheel remains sturdy.

    Rim Tape

    • An inner tube is installed inside of each tire such that it rests between the walls of the rim. The spoke heads create a sharp edge that can cause tears in the inner tube once it is inflated. Therefore, rim tape is installed along the entire inside of the rim to create a barrier between the spoke heads and the inner tube. Some rim tape is adhesive, while other forms simply rest along the edge of the wheel and are held in place by the inflated inner tube. To be effective, rim tape must cover the entire inner edge of the rim; otherwise the tape may shift, exposing any sharp edges of the spoke heads or inner rim construction.