Originally Posted by
noobinsf
Wow, thanks for this info... The seat post that came with it, and appears to fit, is a 27.0. Does that reveal something definitive?
It's almost certainly Ishiwata 024, as 27.0mm would be the correct size post and it's an appropriate tubeset given the level of workmanship on the frame. The only Tange possibility would be Champion Pro but that seems unrealistically optimistic given the mass production workmanship and Ishiwata fork.