Originally Posted by
3alarmer
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...with that rear cable stop for center pull brakes, and the above the BB shell cable routing for the derailleurs, I'd put that one at no later than sometime in the 70's. Also, the seat tube angle looks pretty slack to me, so maybe not the best choice if you prefer a shorter top tube. I have a couple of bikes by Bob Jackson, one of which is probably contemporary with that one. It's a pretty solid bike.
Good point on the cable stop. 70's seems like it could be right. My understanding about the cable routing is that BJ kept the above BB routing much later than everybody else. I'm still trying to gather a consensus on Bob Jackson information, though. Don't know that much yet. Noticed the slack seat tube, but the top tube tube measures 22", according to the seller. That should be just right.