Originally Posted by raywood

I have a worn-out 700 x 32 tire on a rim whose label says ETRTO: 622 x 18. The replacement that I bought says 700 x 38B. It also says 40-635.

I knew I was getting a wider tire. That part was intended. I also knew I was getting a great price. So I went for it. It was only later, when it arrived, that it occurred to me that the letter B might have some significance. Seriously, I thought I was supposed to watch out for HB, which would have been wrong. Somewhere, I got the impression that letters like B and C were outdated. But the bead on this B tire, the way it curves out, does not look familiar. I'm also not recognizing the 40-635. I don't recall seeing that in the sales literature.

So, the question: did I buy the wrong tire and, if so, the more important question: why is it wrong? What did I buy? And what will happen if I mount it on this rim -- assuming it will fit correctly, regarding which I'm not entirely sure whether misfit would be obvious to me.