Match the tube size to the tire size, no matter the rim width. I've miss matched tube\tire sizes and it worked but it's easy enough to match them. Smaller tube mismatch was easier than larger tube mismatch because it can get mighty crowded stuffing a too large tube into a tire.I have 4 MTB's and all are tubeless. I have a Santa Cruz Stigmata I am using heavily for road use. I have 2 sets of rims. WTB i19 AL and NOX Skyline CF. So internal widths of 19 and 23mm.
I've never had a road bike and no experience with tubes. How do you size a tube for a 19 or 23 wide rim? Can you put a tube rated up to 23 in a 19?? How about a 23 in a 33 tire? IDK...how does it work?