The SBX frames came out around '93, and like the Formula frames it was a special tube set for Bianchiwith that oversized and ovalized downtube. I don't know about the sponsorship thing, I know Bianchi did some sponsoring back in the '80s. I am pretty sure these came with a Columbus fork but l'll have to look that up when I have time tomorrow evening. These came as a complete bike, don't rember the group, or as frame/ fork
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk