I think you could just change the shifters and FW and be good to go.
Don't forget you need a pair of those little adjustable cable stops that replace your down tube shifters, and why not some new cables while you're at it?
Or if you can find some 10 speed Ergos, they'll run a 2x7 or 8 speed STI system just fine. A few years ago I got Veloce shifters from Ribble for my BIL's bike but I haven't shopped lately... yep, still around for $90-100. They came with a complete cable set and the left shifter had enough clicks for a triple even though sold as a double - excellent value. I suspect that current Tiagra 4700 shifters would also do 7-8 speed SIS but have no confirmation
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Genesis 49:16-17
Last edited by Darth Lefty; 07-19-19 at 01:55 PM.