I've got a couple of nice Centurion road frames from the 1980's:
- 1984 Comp TA, Tange Champion #2 tubing, 63cm (ctt) seattube, 59cm top tube
- 1987 Ironman Expert, Tange #1 tubing, 64cm seattube, 58cm top tube
And I'm wondering about the difference in their tubesets. I know that Tange #1 used in the Ironman Expert is slightly heavier than Tange #2 produced at the same time. According to the most knowledgeable-sounding post in this thread, Tange #1 wasn't heavier because it was lower-end, but rather because it had thicker-gauge top- and downtubes to better deal with frame flex since lugged frames couldn't use oversized tubing.
The Tange Champion tubing used in the 1984 models seems to be reverse. Champion #2 was used in the Comp TA (Centurion's second-highest model, came with Shimano 600) and Champion #1 tubing was used in the Turbo (Centurion's top model, came with Suntour Superbe Pro components).
I'm curious as to the relationship between the Champion #1, 2, etc. tubeset and the Tange #1, 2, etc. tubeset used a few years later. Basically, I'm trying to decide how to build these two frames up, and whether I should expect their ride and flex characteristics to be any different from each other.
And this is useful knowledge to have in the database.