# 23-25c tubes on 28c tire?



## dwgranda (Sep 8, 2009)

Went to pick up some tubes at the LBS. Wanted tubes that work with my 25c front and 28c back. LBS only had 23xc-25c bontrager tubes with the valve stem length I needed. Said these would work with 28's. What does the forum say? BTW- I already bought them, just wondering if I'm going to be riding on some maypops.


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## Dave Hickey (Jan 27, 2002)

I'm using 23c tubes with 35c tires.


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## dwgranda (Sep 8, 2009)

Dave Hickey said:


> I'm using 23c tubes with 35c tires.



Jeez, and to think I bought these because I only had 18-23 tubes.


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## orangeclymer (Aug 18, 2009)

you'll be fine.


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## My Own Private Idaho (Aug 14, 2007)

Dave Hickey said:


> I'm using 23c tubes with 35c tires.


I'm using 32 mm tubes in 48 mm tires. It worked for about 1000 miles before I pinch-flatted.


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## Kerry Irons (Feb 25, 2002)

*Stretch*



dwgranda said:


> Went to pick up some tubes at the LBS. Wanted tubes that work with my 25c front and 28c back. LBS only had 23xc-25c bontrager tubes with the valve stem length I needed. Said these would work with 28's. What does the forum say? BTW- I already bought them, just wondering if I'm going to be riding on some maypops.


You may not have noticed this, but inner tubes stretch. Therefore you will have absolutely zero issues when you stretch your inner tubes as described.


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## Mr. Versatile (Nov 24, 2005)

No problem.


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## Mark Kelly (Oct 27, 2009)

Rubber is incompressible so this is very easy to calculate.

Taking 20mm as the effective uninflated diameter and 24mm as the design centre inflated diameter, the tube walls will be approximately16% thinner and under approximately 25% more tension.

Neither of these seems likely to cause any problems, which is borne out by the practical experience in the posts above.


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## bicyclerepairman (Mar 12, 2003)

Only drawback I noticed when I did this was having to inflate the tires a little more frequently. They rode fine, maybe a little better.


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