(long time reader, first time poster)
I bought an old road bike, handbuilt Roberts form around 1975. It's all dura ace and campy nuovo record and very nice.
But it has been geared pretty oddly and is a nightmare on anything not dead flat. it's 13-20 at the back (5 speed) and 55-44 on the front. (170mm cranks and 27-1 1/4 wheels)
at the top end it's fine but at the bottom I'm struggling, especially as it's not keen to go to the lowest gear at the back. So I have a couple of questions ( the chainrings are all DA, with no pegs or teeth to lift the chain):
If I swapped the inner chainring to a 38 or 40 would I be able to shift to the 55 or would the step be too big? and would I need to swap the 55 as well? I'd rather not as it looks pretty cool. I'm guessing the front derailer might not handle that? (it's campag)
If I buy a modern set of chainrings will they fit the 5 speed chain, or how do I know what will fit?
If I buy NOS, where is a good source of chainrings.
Is there a better way to sort this? the rear derailier doesn't look like it would handle a much larger rear sprocket, i'm not sure changing the crank arms would work with the frame size.
Thanks in advance