Originally Posted by
hobkirk
My Roubaix will not (I don't think) allow a 28C tire - insufficient clearance. But I do ride 25C tires (Conti GP4000's since about month 3, but Specialized Roubaix for the last 6 months).
I get nervous about tire pressure (I weigh 230 currently) but I must admit I am allowing the pressure to drop lower than I used to. I press my thumb into the tires before every ride, but I've been going 2-3 weeks between pump ups.
PS - I even spent a month riding with the saddle nose pointed somewhat to the side, like Cobb recommends.
I have 29mm on my tarmac, and basically I just looked at the available space to the brake, seat tube and stays when I had the 25mm mounted and deemed there was enough room. Even with the 29mm Parigi-Rouobaix I still have 3mm to spare, which sounds similar to the Roubaix, since a quick google search mentions someone use a 31mm tire on their Roubaix. But of course it also depends on your rim width. And I use Assos cream but it's the only one I have tested.