Originally Posted by
HTupolev
Racing derailleurs back then were limited to a much narrower overall range, but not to tight spacing from cog to cog. For example, nearly all of them circa 1970 could handle at least a 24T cog; a 14-24 freewheel has an average step size of about 11.4% and might look something like 14-16-18-21-24. That's not tight-ratio at all!
My 1972 ItalVega Super Speciale with a Record groupset had 13-26 in the rear and (I think) 52-39 in front. The bike weighed 23 pounds (it had Columbus tubing).
I have no idea how I climbed in 39/26 gearing. Nowadays, my lowest is 36/32.