Re: Campy chainring, 148bcd
I am thinking this sounds like an october fool's joke, or maybe you are looking for 151bcd. One of our San Diego LBS's (I think Cal Coast Bikes) has campy 151bcd rings, although 42 is not humanly possible in track pitch. In general, you get about 1 BCD for every 3.4 mm of chainring. So, for a 148 bcd crank, minimum would probably be 43T, and for 151 bcd, minimum is about 44T.
In 144 bcd, NOS 42T campy rings are still quite available in 3/32 (like the guy at the local san diego high tech swap meet 4 months ago). Two possible workarounds :
(a) If you really cannot find a 43/44 ring in 148, maybe there was a place in Japan that would custom-make one for you. You might even be able to get 42T if it's truly 148 bcd - just barely. I think that if 148bcd exists, campy probably didn't make it because this size would likely put wear on the spider. Unfortunately price is probably about $130 shipped.
(b) If it really is 148 bcd, perhaps you could find a smaller ring (such as SR 118 bcd) and do a number on it with a dremel tool and some files. A little 30-minute number. I love my little dremel. When it spins up to 22,000 rpm, all the aluminum parts in my garage bow down and pray for salvation ...
- Don Gillies
San Diego, CA