- Put that old paintbrush away – there’s a boy in town. Reaching the deepest and darkest parts of your drivetrain can be a challenge without the right tool. That’s why we developed our high-quality Drivetrain Brush. Boasting a mean, all-black finish, this is the perfect bit of equipment to apply our Bio Drivetrain Cleaner to your chain, cassette, mechanics and sprockets in no time.