Drum brake shoes for the AD-50. The shoes expand inside the brake drum and slow the wheel through friction of the friction linings.
Replace them as a pair when the linings are worn down, the brake has become weaker, a grinding noise has appeared, or the brake lever travels almost all the way. Keep the drum clean: oil or dirt on the linings badly impairs braking. The shoes are replaced as a set per wheel; breaking in a new set takes a few dozen kilometers of gentle riding.
