Originally Posted by
masterchief
I'm looking for any comments and opinions on why this is or isn't a good spec.
No go on that rear derailleur with the shifters you want.
But with the gearing you list, you can just use the Tiagra 4700GS rear derailleur.
4700 shifters need 4700 derailleurs. Same with current 105 shifters- they wont work with mtb or lower # derailleurs. Its what Shimano has steadily moved toward with any current STI shifters that have cable routing under the tape.