Totally new at this and I find myself in a funny situation. What I currently have a 2010 Tarmac comp with 105 components. Somebody locally is selling a Roubaix S-Works for soo cheap I NEED to buy it I find myself in a situation where I might just ride it and see if I want to keep it. If I would rather keep the Tarmac maybe swap out the parts if its possible? Maybe even sell it if I dont like it? I need to get in contact with this guy I don't even know the size of the Roubaix. His description is "roubaix carbon fiber w/ dura ace components" Hell I might keep em both as is. I test rode a Roubaix and liked it but ended up going with the Tarmac. I like my Tarmac but I rode my friends Allez with Ultegra parts for a week and really liked it, so I am guessing the Dura Ace parts have to be a good upgrage. I searched a bit and didn't find much. I found some website that had some sort of interchange chart but couldn't really understand it. Sorry for being such a noob at this, I will like my other hobbies eventually get their!