Bearings specially designed for frame joints The black bearing max bearings are made of steel, they are originally mounted by the vast majority of cycle manufacturers (frames, wheels, pedals), urban sports. Technical features: more balls, 2RS seals, waterproof and dustproof, more grease than standard bearings. International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions.