Don't get me started on bicycle wheels. My wife and I both had wheels nominally of the standard size (28 inches). Guess what -- standard 622 ("28 inch") tyres d

Don't get me started on bicycle wheels. My wife and I both had wheels nominally of the standard size (28 inches). Guess what -- standard 622 ("28 inch") tyres did not fit either of our bikes, but her wheels were too small, and mine were too big! So we have two different bikes both ostensibly of the standard size, but both differing from it in different directions! (Yes, I have looked it up on Sheldon Brown's bike tyre sizing guide -- there are two different sizes that are almost the standard size but not quite, one too small, and one too large. So this is not just our bikes that were faulty, these weird sizes are out there.)