# safe to use 700x18/20c tube in a 23mm or 25mm tire?



## czacharyasz (Dec 24, 2009)

i was bout to order a few replacement tubes, just wondering if its safe to use this size in a 23/25 tire....since i have both size tires on different bikes. they are the kenda super lite tubes (ive always had good luck with ultra light tubes) . 

The other option is the 700x23/25c tube....but if the lighter tube fits then thats what ill go with..

some of the tubes says pv/60mm....does that mean its the longer presta valve for carbon wheelsets? New to road bikes so id appreciate the help...


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## mpapet (Dec 2, 2009)

I've never had problems with what you are describing. I've been doing it for more than 20 years.


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## Guest (Jan 15, 2010)

It'll be fine.


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## ZoSoSwiM (Mar 7, 2008)

Some have suggested that you'd be over stretching the rubber so you'd be more prone to flats. I've always felt that a flat is going to happen regardless of the tube.. Glass and such cuts rubber no matter how thick.


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## Hank Stamper (Sep 9, 2009)

It'll work but I don't get the logic behind not just getting the correct ones.


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## wim (Feb 28, 2005)

czacharyasz said:


> some of the tubes says pv/60mm....does that mean its the longer presta valve for carbon wheelsets?


Yes, 60 mm long valves generally used for deep section (sometimes oddly called "deep dish") aluminum or carbon rims.


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## PJ352 (Dec 5, 2007)

As others have noted, it'll work, but at $4 +/- per tube, why not keep both sizes on hand?

The 60mm designation relates to presta valve length. The longer lengths are needed for any deep V rims, not just carbons.
EX:
http://www.nashbar.com/bikes/Product_10053_10052_175664_-1_201492_10000_201496


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## |3iker (Jan 12, 2010)

I suppose one is up-sizing the tire and want to keep using the old tubes (rather than throwing them out) and replace as needed.

how about a 23mm tube on a 28mm tire?


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## Guest (Jan 15, 2010)

still fine.


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## Mr. Versatile (Nov 24, 2005)

If you can't or won't buy the correct size because they're not on sale, or out of stock, I wouldn't worry about it. I'd be more concerned about putting a tube sized for larger tires in a smaller tire, e.g., 25-28 mm tube in a 23 tire.


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## Mr. Versatile (Nov 24, 2005)

While riding, I came across a guy on a MTB with a flat on the front & no spare. I don't remember for sure, but his tires were~26x30+. I loaned him one of my spares, a 700x20-23. We put on the front wheel and he made it over 10 mi. to the closest LBS without problem.


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## ben91 (Dec 5, 2009)

The tube will stretch to fit the larger volume tire. Never had a problem.


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