Hi everyone...sorry if this has already been discussed. If it has, I've been unable to find it. My question concerns the 1988 Miyata 512. I know the main tubes use triple butted splined tubing. I've looked at the scanned catalogues on blogspot and it looks like the 712 models and higher from that year were made with chromoly seat and chain stays. The catalogue does not specify what the seat and chain stays on the 512 are made with. I'm assuming hi-ten straight gauge but it seems odd to make a frame with triple butted splined main tubes and low grade straight gauge for the seat and chain stays. If anyone has more info, I would greatly appreciate it. Here is the page of the catalogue I am looking at:

http://bp1.blogger.com/_whtVpXkKwlQ/...0-h/img177.jpg