Bicycle Mechanics - Will 700x18/20C tubes work a 700x23C tire?

Sorry if this has already been gone over. I did a quick search and found nothing.

I got a real good deal on some Kenda Superlite tubes in 700x18-20C size but I run 77x23C Vittoria Corsa evo CX tires and was wondering if it is safe to use these tires?

I'm guessing 3mm isn't going to make a difference but figured I better ask someone that may know more then me..... The last thing I want is a front tire flat while going downhill at 45+ mph. :o

Thanks in advance for answeing my stupid question :)

They are fine, in fact, a lot of people prefer them as they are easier to install. The downside (albeit slight) is the rubber will be slightly thinner as it stretches to fill the 23 tire.

Thanks for the quick reply. I didn't think I would have a problem but figured it wouldn't hurt to ask.

Not only will those tubes work, but those are what you should use. The inner width of the tire is smaller then the outer width.

Lol I had the same question but was too afraid to ask. Thanks :)

I believe the size on the tube corresponds to the size of tire they are meant for. But I also agree that they should work fine in your 23's. I prefer ultralites myself.

Al

Not only will those tubes work, but those are what you should use. The inner width of the tire is smaller then the outer width.

Huh?....Tube sizes are based on the tire size. 700x18/20 tube is designed to fit tires sized 700x18/20! It's not somehow based on the interior size.

That said, it should work just fine. The only problem is if you have a tube with a stiffer cross section at the valve, it may not be able to expand much further and may rip.

using smaller tubes is a very cheap alternative to using ultralight tubes :) and the result is the same.

- Joel