The size of your tube doesn't matter that much. Really.

Once again, a reader has come to the authority and asked Cycledork.

Dear Cycledork,

We've had an exciting weekend of assorted flat tires and tube mishaps, so now is a good time to ask a question about tube sizing. The tires on my Giant OCR3 are 700 X 26C. On getting home from picking up a replacement tube (and CO2 canister) at my friendly neighbourhood bike shop today, I noticed that the box says 700 X 23/25C. Now they definitely heard me when I said "26" and they always know their stuff, so I'm assuming that this tube is the right size. But what's with the confusing numbers?

Curiously,

H. Trouser

Dear Mr. Trouser:

I'm sorry to hear about your flats and tube mishaps. The good news is your latest tube should fit your wheel and tire just fine. According to Giant, the OCR3 comes with 700x25 tires so a 700 x 23/25 tube should be fine, even in a 26 . Tirewise, the "700" refers to the diameter of the wheel in millimeters (it comes out to about 27 inches) and the "23/25" refer to width, also in millimeters (a hair less than an inch). Tubewise, the 2100, not terribly different than the OCR3, came with 25s. I've been using 23s for several years. You can probably go as skinny as 23 or as fat as 28 or so. No big deal. Ride and be well.

Yours in velophility,

Cycledork