Reynolds never made butted rear stays that I know of.
Off-topic Ritchey "Logic" chainstays were made truly butted (maybe still are made), the only ones I've ever heard of; and no one ever made a butted seat stay to my knowledge.
Choose rear stays for the intended purpose by size (diameter), shape and wall thickness.
Most all chainstays in the CR period were the same size, 7/8" or 22.2 mm, and roughly the same shape (round) except for the tire/chainring clearance scheme, so it pretty much just comes down to thickness. Don't believe the hype that a chainstay can be made stiffer by pressing it into a diamond section (De Rosa) or curving it (Hetchins or Serotta).
Seatstays varied more in diameter so there's a little more to think about there, but the effect on ride is minuscule. Stiff is good if you use panniers or cantilever brakes, otherwise might as well make 'em light.
You may consider all of this pure opinion since I won't give any proof, but I feel it's well backed up with theory and practice, and most engineers would agree with most of it.
Mark Bulgier Seattle WA USA
Donald Gillies wrote:
>
> "You are making a reynolds 531 sport-touring frame that's 24.5" large.
> It's not a loaded tourer, and its not a road-racing bicycle. What
> butting profiles would you use in the rear triangle."
>
> With this information, I could dig hunt around on the novacycles
> website and decide for myself if plain-gauge tubes vs. butted rear
> tubes might reduce frame weight by about 50 grams ... I had always
> thought the savings of going to a butted rear triangle would be much
> more than 50 grams.