I recently bought a Giant OCR-2 with the Tiagra shifters and front derailleur. I noticed fairly quickly that it didn't like to shift to the smallest chainring, but I wasn't fussed about it (flat terrain locally), and figured it was a minor adjustment issue that I would get around to sometime.
Last week, I suffered a moderate wipeout, and sent the bike to the shop to be completely checked over. The shifters suffered some minor cosmetic damage, but certainly nothing serious looking.
When I got the bike back, it was clear the shop had completely botched the derailleur adjustments, so I took it upon myself to adjust them (I even downloaded the service data from Shimano...). With the cable on the front derailleur disconnected, I discovered something I though very odd - the front shifter seems to have FOUR positions. After much fiddling, I now how what I think is a working setup, and I can now get the chain on the smallest chainring. The "extra" position generally keeps the chain on the intermediate chainring, and is somewhat useful in that I can eliminate chain rub on the front derailleur through the whole sprocket range.
But is this normal? Maybe I am old fashioned, but I assumed the front shifter would have THREE positions to match the number of chainrings... Have I messed up the adjustments completely? Is this thing going to self destruct on the next long ride?