What the heck? Why does tire manufacturers market one tire sizes say 700 x 38c on the sidewall, but the ETRTO is 40-622? Here are two examples, one from Vittoria and one for Panaracer. I understand tire width will vary based on rim internal width, but why would you have 2 numbers?
That's weird...700x38C ought to be labelled 38-622. This is also true according to biketiresize.com, which provides a definitive-ish comparison of various tire measurements in ETRTO (e.g. 40-622) vs. 'French' (e.g. 700x40C) measurement systems. But strangely, according to the site, the ETRTO measurement for 700x35C is 700x37C.
Yeah - it doesn't help but we can continue to vent online I guess!
More "scary" is the new 650b size on the Vittoria line
650b x 40 = 47-584
7mm difference?? WTF? Based on what I've seen online Vittoria gravel times are true to width if not a bit wider. Some people might run into clearance issues if they bought that tire.
