I'm thinking more like early-mid 80s because of a couple of features -

One: The brazed-on toptube guides. Most 70s bike used chrome (or plastic) bands to hold the rear brake cable.

Two: The shifter bosses. They were clamped-on in the 70s. Brazed-on downtube shifter bosses came about later....

Three: Water bottle boss. Again, no braze-ons even on mid-70s bikes.

Look at my '75 Fuji S-10S



No braze-on cable guides, shifter bosses, or water-bottle bosses.

And notice the 'graceful curve' of my 70s Japanese bike fork...

However, by the mid-late '80s, Aero brake levers were becoming more common.


Soooooo..... My guess is more of a late 70s / early 80s frame.




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