This is a nitpicky question for what is basically a yard sale find, but it's my first steel roadie since the late 80's (won't be my last) and I'm curious...
I recently acquired a Bridgestone 450. Looks pretty much like the one in the 1987 catalog here:
http://www.sheldonbrown.com/bridgestone/1987/index.htm
I noticed that the catalog's descrition of the frame material simply says "CrMo triple-butted tubing" but the descriptions for the higher end models (the 550 and T700) seem to provide more detail, like "CrMo triple-butted tubing" but also specific info about seat tube and chain stay - "CrMo tapered seatstay" "CrMo chainstay."
Should I assume the seat tube and chain stay on the 450 are not actually CrMo? Might explain the 2-3 extra lbs the 450 carries over these models...
-sruti