Indeed, Giant did make use of simular drop outs. Instead of the hole there was a Giant logo. And... Giant did make lugged frames. See for example the Giant Peloton Superlite. The blue/purple ones in earlier had those drop outs by the way...peetee":2w2dmjar said:Those rear dropouts remind me of the ones Giant used but I have never seen a lugged frame from them.
peetee":20uum7ig said:I am pretty sure it’s not 531 too. Those seat stays are too chunky, especially at the bottom end.