I think RSX only very briefly went to 8 speed shortly before becoming sora. Again, I don't know anything other than that I have an RSX 8 speed triple crankset I'm about to install on my bike and when I was reading (I think on Sheldon's site) about it they made it sound like it was a brief unpopular run. Maybe it was only the 8 speed triples that were unloved. Since I'm the same guy who was all screwed up earlier don't listen to me, but I think 8 speed was only in 97-98 or 99 right before Sora, so if it's older than that, I'd guess it's 7 spd.
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Bikes: 1996 Eddy Merckx Titanium EX, 1989/90 Colnago Super(issimo?) Piu(?), 1990 Concorde Aquila(hit by car while riding), others in build queue "when I get the time"