Little thing about bicycle tire sizes

Not a major deal here, but when I'm reading tech bicycle email lists (such as these excellent ones) and Americans refer to tires using ISO rim sizes such as 559, 571 and 584, it makes me edgy. (Europeans and antipodians are excused at this point.)

Now, the systems for measuring bicycle tire sizes are a huge mess for a variety of historical reasons, as Sheldon Brown does a good job of explaining. But he neglects to mention something, and no one else ever seems to want to bring it up either. I keep wondering whether that's because it's so obvious, or because no one even realizes it.

I sure get the impression that most American bike riders don't know that a 559mm rim (standard mountain bike) is exactly 22" in diameter, a 571mm rim ("650c") is exactly 22.5", a 584mm rim ("650c") is exactly 23", and a 622mm rim ("700c") is exactly 24.5" in diameter.

Where did you think those funny metric numbers came from anyway?

Sure, it's important to know the metric dimension since that's how they're sold and what the rest of the world uses. But for us Imperial girls still living in an Imperial world, the size in inches tells us how big it really is, in an intuitively useful way.

Same deal with 35mm photo film, if you didn't know. Measure a piece some time. It isn't quite 35mm wide, but it's exactly 1 3/8" because Thomas Edison designed the film format (for motion pictures) and he never used metric units.

Should there be some kind of a clever name this kind of non-metric metrification?

If you haven't discovered Wikipedia yet

I guess Google started giving me hits on Wikipedia a year or so ago, and by fall of this year I was going to Wikipedia first for a lot of my queries. The Guardian ran a story about it in October, which I read for the first time yesterday.

Not everyone loves it, but I'm suspicious of a lot of their reasons for not liking it. "Librarian and internet consultant Philip Bradley," whomever and whatever that is, complains about "the lack of authority." Maybe that's a problem for him, but woe be unto any normal person who takes information from any single source as the absolute last word. You can find mistakes and misinformation anywhere, but when so many sources are available on the Internet, why would you ever not double check?

More annoyingly, Encyclopedia Brittanica Editor-in-chief Dale Hoiberg opines:

People write on things they're interested in, and so many subjects don't get covered; and news events get covered in great detail. The entry on Hurricane Frances is five times the length of that on Chinese art, and the entry on Coronation Street is twice as long as the article on Tony Blair.

And a big "so what?" to that. It's only a problem to people who think their customers are still making a choice between dropping multiple Madisons on a bound edition of EB versus some other hard-copy encyclopedia. Or deciding whether to pay for their ridiculous online subscription plan versus some competing service. (Are there any?)

No such either/or choices are called for. Wikipedia does what it does, a lot better than you'd think it could, and I can follow links or use Google to check facts and get other perspectives. And already other wikis and pedias are popping up to handle topics that Wikipedia doesn't cover as well.