If uncoated balancing weights are mounted on a rim, it may come to contact corrosion. Contact corrosion occurs when metals with different nobility are in close contact. The more noble metal enhances the corrosion of the less noble metal. The condition for this process is a corrosive media between the two metals, like rain water or simple humidity.
Coated balancing weights preserve any rim from damage due to contact corrosion. The high quality OEM coating protects the weight optimally against environmental influences, even under extreme conditions. See comparison coated / uncoated weights in self-test on the right side. All weights are correspondingly subjected to OEM specifications 480 hours salt spray test according to DIN 9227 and ADTM B 117-73.