Chain, rear, 520, 100P, Norton, Regina

Rear chain, 520, 5/8 x 1/4 in [actual dimensions 5/8inch x 0.265 inch (6.7mm)] , 100 pitch, Regina with joiner. Max pin length=16.6mm; pin length joiner: 17.64mm. Very close but slightly wider than a Renold Synergy 110054.
88P = ES2: 1949-51
89P = 18: 1948-53. 19R: 1954-55. 19S: 1954-58. Model 7: 1948-51
90P = Big 4; 16H: 1946-7; 1949-54. ES2: 1947; 1952-53; 1954-56. Dominator 77: 1957.
91P = Big 4; 16H: 1948; Model 18: 1946-47;  ES2: 1948; Model 50: 1956/58; Model 7: 1952-55. Inter 40: 1948-51. Inter 30: 1946-51
97P = Inter 40; Inter 30: 1954-55. 50: 1963. Dominator 88: 1961-64. Dominator 99: 1956-57. Dominator 650: 1961-64.
98P = Dominator 88: 1953-58. ES2: 1963. Dominator 99: 1961-62.
To make an even number remove links. To make an odd number you also require a half link and another joiner.
Any length can be provided on request.
Note: Use any other chain on a Norton and risk wearing away the primary case, chain guard and gearbox shell. Renold Synergy chain lasts up to 6 times the life of other brands see Renold synergy website.