Originally Posted by
One Wheel
8mm clearance on all sides, could go 8mm x 2, but that would rub a bit. 32 + 16 = 48mm would rub, 45 is probably safe especially figuring that it will almost certainly inflate smaller. Not saying my math is right, that's just the math I did.
38 seems like a reasonable figure to try. Definitely looking for a slick, not a knobby. I'm liking what I see for Panaracer GravelKing Slick, Rene Herse (Barlow Pass) and also Continental GP 5000 but those only go up to 32. Any recommendations between those or something else? Teravail Rampart is also available in 38, and has the advantage of being the same model that's served me well in 32.
If your tire is 30mm wide and there is 8mm on each side, that's 46mm of space. A tire that is 45mm wide when spacing is 46mm is crazy tight. Even if the tire is 45mm and measures 43mm, that's still crazy tight to me on a gravel bike since it's only 1.5mm of space. Clearance that tight would create scraping for me even on regular dry roads.
A GK Slick is pretty solid for a mix of price, durability, and rolling resistance.
Continental Terra Speed in a 40mm rolls fast and that model line tends to run narrow. So between the narrow rim and undersized width, that could work.