The wheel of the bicycle is composed of a rim, circle, hub and spokes. These are made of steel or stainless steel. The most used diameters are 2 mm or 1.8 mm. The most common colors are black or steel color. For a 700C diameter rim, 32, 36 or 40 spokes are generally used. A rusted or broken spoke is very easy to change. We unscrew the rim nut so we can remove it easily. Sometimes, the spokes can become loose, to tighten them, we will use a spoke wrench.