Have a question for Lennard? Please email him at email@example.com to be included in Technical FAQ.
With regards to sizing tires to rims, You said, “A general guideline is to take the inner rim width and multiply by 1.25 for the minimum tire size and by 2.5 for the maximum tire width. So, a 22mm inner rim width should not have less than a 27mm-width tire on it, and no bigger than a 55mm tire.”
Can you address if this is the “printed” value (which assumes a given rim chosen by the manufacturer which results in some 23s by one manufacturer being wider than 25s of another manufacturer when installed on the same rim) or is this the measured value when installed on the rim in question? (In which case Don’s 23s measuring out to his frame’s 26 limit would seem to be on the cusp of meeting the “general guideline.”)
It’s the size indicated on the side of the tire.
Drag caused by tires comes from both tire hysteresis and aerodynamic drag.
Thanks for the thoughtful discussion regarding all things and in this case rolling resistance. As is sometimes the case, going for a ride brings me some issues to ponder and think about: