The Record hub bodies were a one-piece design, made from a forged aluminum shell, with replaceable steel bearing races pressed into it.
A cable through the center of the spring would pull the jockey/tensioner to the desired cog.
These are generally called "plunger-type" derailleurs and were produced in huge numbers.
Here he is leading on the Aubisque in the 1954 Tour de France. Racers used to fear the extra friction of a second derailleur pulley and were willing to sacrifice shifting performance in return for the perceived drag reduction.
Later measurements showed the energy loss from the second pulley is negligible.
It wasn't the right sort of bike for derailleur gears, but the 4-speed was fine, given that most racing bikes at the time only had 5-speed freewheels. Then one of them, Shaun Mitchell, got a second-hand "proper" racing bike.
It was a Freddie Grubb frame which I think he picked up in one of the second-hand bike shops off Shields Road in Byker.They were for sale at the most amazing garage sale a teen-aged (or even middle-aged) bike geek could imagine.Besides the hubs, I had purchased a pair of impossibly light Super Champion tubular rims and built my first pair of wheels. It has some 60s era parts on it (ie Campagnolo gran sport rear derailer)and a steel crank-set marked Legnano also. Someone has suggested the 75 in the serial number is the date, but it seems way older than 1975. Hi Blakemo, First Ill provide a little background to Legnano bikes followed by information about your specific frame.Since 1902 the name Legnano has meant quality, reliability and style in bicycle production.My father said something along the lines of "about time you had a bike," and in we went.