Range for 70's Campy Nuovo Rec ?

Bob writes:

What's the range that a Campy Nuovo Record rear can handle for
sprocket and tooth difference at the front ? Does it typically have
enough horizontal throw to handle a 7 speed freewheel ?

The original rear derailleur range was rated at 24T, 27T maximum rear
sprocket but many people push the maximum rear cog to 28T. This
usually meant a 42-52T up front and 14-28 freewheel was the most that
nuovo record could handle. I have known of bikes with the following :

54-46 and 14-28 my schwinn P-15, i changed it to a P-10
52-44 and 14-28 a really old 1970 raleigh international
52-42 and 14-24 the later raleigh internationals
52-42 and 13-26 the stock 12-speed gears on a raleigh pro

When running a 28T freewheel, you need to be very careful with
derailleur angle adjustment and dropout adjustment to maximize the
space between the upper pulley and the largest freewheel cog. My P-15
sometimes "sticks" when I'm trying to shift out of the 28T gear in the
back.

I've heard people claim they can shift 30T in the rear but these are
the same guys claiming they got their steel bikes down to 8 lbs by
drilling out parts ... sheesh ...

- Don Gillies
San Diego, CA