This a.m. I excidetly got up at 5:00 a.m. and was out the door by 5:20. With the time change I can see in the morning and am now back to my sort of daily routine of riding for an hour or more before going to work. It is wonderful riding while the sun comes up. Then it happens a few miles away from home I get a flat. I take out my tools an change the tire only to find that my tube is too big. It was a 700 x 23, my tire was a 700 x 18. Luckily I had a 700 x 18 in my bag, always carry 2 tubes.

So am I stuck always worrying about having the right size tubes? I can never borrow anyone else's tubes then? Or is this a common size?