Joined: Mar 2005
Posts: 169
Likes: 0
From: Cleveland, Ohio, USA
Bikes: KHS Solo One (2003), Cannondale 29er (2007), Giant Iguana (2001), Cannondale SystemSix (2007, race set-up), Gitane Sprint (trainer), Cannondale CAAD 8 back-up, Cyclocross 2005 (105/Ult), Cannondale Ironman TT 2006
I believe your Sora drivetrain has an 8 spd rear cogset. You will need to do more than get Tiagra brifters. You'll need to add a new 9 spd cogset to the list. The rest of your drivetrain should work with the 9spd upgrade.