Sorry to hijack thread but I have just picked up a Corsa. I have a couple of questions.
How do you tell if the frame is 501 throughout? What groupset would of been fitted originally? I need a new freewheel, should it be 10 or 12 speed? And what ratios?
Well, you don't say whether you have a bike or a frame...if the bike is original then the 501 sticker is the giveaway (it'll state maintubes, forks and stays) - I belive later Corsas only had 501 maintubes and forks.
Most bikes of this period have 6 speed freewheels, the Corsa is no exception (originally a Shimano cassette 13-24), with a Shimano 105 groupset.
Photos would be useful if you want more info.
Co-founder of a V-CC section, member South Eastern Road Club and owner of - 2005 Bianchi Reparto Corse (modern), 1985 Raleigh SBDU Pro Super, 1984 Raleigh LU Corsa, 1980 Allin Stan Butler Special, 1978 Ron Cooper, 2 x very early Roberts (late 60s/early 70s), 1975 Bill Philbrook tourer, 1966 Raleigh Superbe Roadster, 1964 Allin Stan Butler Special Belgique, 1951 Hobbs of Barbican S/C, 1950 Hobbs of Barbican S/C, 1947 Hetchins Super Special, 1908 Centaur Featherweight. 1988 Specialized Stumpjumper.