Joined: Mar 2014
Posts: 18,205
Likes: 6,605
From: ,location, location
Bikes: Foundry Chilkoot Ti W/Ultegra Di2, Salsa Timberjack Ti, Cinelli Mash Work RandoCross Fun Time Machine, 1x9 XT Parts Hybrid, Co-Motion Cascadia, Specialized Langster, Phil Wood Apple VeloXS Frame (w/DA 7400), R+M Supercharger2 Rohloff, Habanero Ti 26
if the Tiagra is 4700 then you need either 11 speed or 4700 rear derailleur. If it is 4600 then you can use any ten speed road derailleur. I personally really wouldn't use derailleurs or shifters from Tiagra but if I really needed a budget bike 4700 isn't so bad. 105 is generally my lowest on the road side.