Use on front or rear Economical Great quality DIY & save money Brake drum shoe set with springs, with a diameter of 105 mm This size is used on several scooter and moped models, including the Tomberlin Firehawk mini bike Brake drum shoe set with springs, with a diameter of 105 mm. This size is used on several scooter and moped models, including the Tomberlin Firehawk mini bike. Outside diameter prior to installation is 105 mm, or about 4-1/8″. Can be used on the front or rear depending on the scooter or mini bike application.