The V brake is easy to slip in rainy days, mud or wading roads, and the friction generates heat for a long time. The braking effect is reduced. Too much force will cause the tire to lock. Improper installation will cause the rim to deform. Bad brake pads will damage the rim and even the rim to crack. Bad rim may cause insufficient brake strength and service life. When braking for a long distance, the flexibility of the rubber will cause the friction surface to overheat, resulting in brake force attenuation or loss.