The primary modification
This is the most obvious conversion on this bike. When it was built in the late 1960s or early 1970s this bike would have had an internally geared 3-speed Sturmey-Archer hub. That's gone. Instead it's been built up with this recent Shimano five-speed freewheel. This certainly worked (though it won't now--that freewheel is rusted and shot), but it's hardly true to the original design.
The most annoying part about this is that whoever made this switch must have removed the bike's chain guard, since it wouldn't fit with this new setup. That's a sad loss on such a quintessential road bike.
UPDATE: I've since learned that this bike was almost certainly a five-speed from the start...ironic, given the three-speed setup that I've given it. But this freewheel was certainly a replacement, given both the brand of the derailer and the way that one of the gears is completely unusable.
The primary modification
This is the most obvious conversion on this bike. When it was built in the late 1960s or early 1970s this bike would have had an internally geared 3-speed Sturmey-Archer hub. That's gone. Instead it's been built up with this recent Shimano five-speed freewheel. This certainly worked (though it won't now--that freewheel is rusted and shot), but it's hardly true to the original design.
The most annoying part about this is that whoever made this switch must have removed the bike's chain guard, since it wouldn't fit with this new setup. That's a sad loss on such a quintessential road bike.
UPDATE: I've since learned that this bike was almost certainly a five-speed from the start...ironic, given the three-speed setup that I've given it. But this freewheel was certainly a replacement, given both the brand of the derailer and the way that one of the gears is completely unusable.