Originally Posted by Nubie

Just wondering if the OP ever discovered the answer to her/his question. I also recently bought a Diverge (aluminum) and my cousin purchased a carbon version. Hers comes with 38mm stock knobby tires, mine with 30mm smooth ones. I'm looking into knobbier tires so we can do trails together, not sure what width I should get. I read that 38mm was the max my aluminum frame could use, 42mm for carbon. Is this true? I only read this in one review, all the others I've read state that 42mm is the max, making no differentiation between aluminum vs. carbon frames. Can anyone clarify?

Thanks!