Hello forum, I am building up the rear wheel of the SF2, and with the bike came a bag of bits marked rear wheel, in this bag is a alloy washer, does anyone know if this is a part of the rear wheel/ brake. Also I only have 1 spring for the brake linings, I know I need another one, is there only 2 or is there 2 large and 2 small springs as noted in a parts book ???