Is my Tiagra rear derailleur missing a screw? Just flipped my bike over, spotted this hole in the underside of my Tiagra derailleur. Looks like a screw should be in there, but there it is not. Should there be? Should I worry? What is this screw for/called?
If no, what purpose does this bike serve?
Note these are pics of the underside of the derailleur.
I'm not sure if there are different Tiagra rear derailleurs, but if you look at the exploded view of the Tiagra RD-4700, I don't see any screws coming in from the underside (except for the bolt that clamps the cable), so I don't think you're missing anything.