truing

Truing is the process of making a bicycle wheel run true: the rim is aligned so it spins straight and round in relation to the hub and brake track. It is achieved by adjusting the tension of the spokes around the wheel. A wheel can go out of alignment in several ways, notably lateral true (side-to-side wobble), radial true (up-and-down hop or run-out), and dish (an offset of the rim relative to the hub center, important on rear wheels with a cassette).

Tools commonly used for truing include a truing stand or mounting the wheel on a repair stand to allow free rotation, a spoke wrench for adjusting nipples, and a rim measurement gauge or runout device. Some technicians rely on visual observation against a reference line, while others use a dial gauge to measure runout.

Procedure typically begins with a spin to identify where the rim deviates from true. To move the rim toward a defect, tighten the spokes on the opposite side or loosen the spokes on the same side; adjustments are made in small increments and the wheel is spun again to check progress. Lateral (side-to-side) deviations are corrected by adjusting opposite spoke pairs around the affected area, while radial (roundness) deviations are addressed by making coordinated adjustments to several adjacent spokes. Rear-wheel dish adjustments may be needed to maintain proper alignment with the cassette and brake components.

Maintenance considerations include avoiding over-tightening spokes and maintaining consistent tension across the wheel to preserve overall strength and longevity. If a wheel cannot be trued within acceptable tolerances, rim or spoke damage may be present, warranting replacement.