What is the function of the lead weights on the wheel rims?
4 Answers
The lead weights on the wheel rims serve to adjust the dynamic balance of the vehicle. The vehicle's tires are also crucial components that ensure safe driving. The small lead weights on the tires, also known as balancing weights, primarily function to maintain the dynamic balance of the vehicle. Most of these lead weights on the tires are internally attached, which allows them to serve their purpose without affecting the vehicle's aesthetics. Although the vehicle's tires and rims are generally circular, due to driving habits, the mass distribution on the tires can be highly uneven. During use, this can lead to imbalances, causing phenomena such as wheel wobbling or steering wheel vibrations. To eliminate such phenomena, it is necessary to add balancing weights—small lead weights—to correct the imbalance of the tires, which is known as dynamic balancing.
The lead weights on the wheel rims are wheel balancing weights, primarily used to ensure the complete rotational balance of tires and rims, preventing the steering wheel from shaking violently while driving. I always tell my friends that during wheel manufacturing, minor unevenness is inevitable, and these balancing weights compensate for such imbalances to ensure smoother rotation. Without these lead weights, the car would experience severe vibrations during driving, leading to faster tire wear and even affecting braking performance and ride comfort. Typically, after installing new tires or repairing a tire, shops use a balancing machine to test and attach small lead weights around the rim edge for proper weight distribution. If they fall off, it's crucial to replace them promptly; otherwise, it can be dangerous at high speeds.
When repairing my car, I prefer to inspect the wheel weights myself. Those small black blocks are attached to the outer edge of the rim to balance weight discrepancies. If you feel steering wheel vibrations while driving, it's likely due to shifted or missing wheel weights. A simple DIY method is to test for vibrations at low speeds, then visit a shop to have the weights reattached. Modern vehicle rims use small lead or similar material clips or adhesive patches to maintain even rotation. Spending a little on wheel balancing during tire changes can save you money on premature tire replacements. Neglecting this long-term accelerates suspension wear, which is not worth the cost.
I've driven older cars for many years, and the wheel weights have transitioned from lead to zinc or plastic patches. In the past, lead was used because of its high density, but due to its toxicity and environmental pollution, many shops now opt for eco-friendly materials. The core concept of wheel balancing remains unchanged—addressing weight imbalances from manufacturing or usage through counterweights. During installation, machines measure the deviation points and attach small lead weights or modern alternatives. If unbalanced, the wheel vibrates eccentrically during rotation, affecting comfort and tire lifespan, so regular checks are necessary.
