Originally Posted by sydney
^^^....My book is from 1974, and list 3 straight gage tubesets in 531. The stuff has been arond since the mid '30s IIRC.
Well, between 1974 and the mid-90's (Nessism's order book) the bike market changed a lot and the demand for straight gauge steel tube sets pretty much disappeared. I'm not surprised the later order form doesn't offer them.