Originally Posted by HillRider
I know from experience that Shimano's MTB front derailleurs won't index with STI brifters. The geometry and cable pull are different. Touring bikes that run MTB cranks and rear derailleurs with STI brifters also run a road front derailleur.
However...it's not a MTB front derailleur. It's a Shimano 443 road derailleur for flat bar road bikes. So, while used currently with a flat bar trigger shifter, the gear capacity and overall movement geometry of the derailleur is all road. That's why I'm wondering why it wouldn't work with STI shifters, even though the compatibility charts say "no". I can't find an appreciable difference. My next step is to measure the actual distance of cable pull in my wife's 105 shifter/FD setup vs. the 440/443 setup on my commuter that I'm pondering converting.
I may just try anyway, and hope it's not too ugly if it's wrong. Front derailleurs aren't THAT expensive.