# How do I pick a tube?



## nate (Jun 20, 2004)

What do the numbers for tubes mean? For instance, I have a Specialized Presta Valve Tube right here that says, "Fits 700 x 20/28C, 27 x 3/4-1 1/8." The 700 is the wheel size, so what is everything else? Will all 700mm tubes work on all 700mm wheels?

What accounts for price difference between tubes, aside from weight? Is there any reason to pick a more expensive tube? Is there any reason not to get an inexpensive tube?


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## Jett (Mar 21, 2004)

nate said:


> What do the numbers for tubes mean? For instance, I have a Specialized Presta Valve Tube right here that says, "Fits 700 x 20/28C, 27 x 3/4-1 1/8." The 700 is the wheel size, so what is everything else? Will all 700mm tubes work on all 700mm wheels?
> 
> What accounts for price difference between tubes, aside from weight? Is there any reason to pick a more expensive tube? Is there any reason not to get an inexpensive tube?


I can answer the first part of your question. The second set of numbers is the width of the tires. For example, 700x20/28c means that the tube can be used with 700cc tires range from 20cc to 28cc wide. 

I can answer the first part of your question. The second set of number is the width of the tires. For example, 700x20/28c means that the tube can be used with 700c tires range from 20c to 28c wide.

As for the second part of your question, the only thing I can thing I can think of might be quality. The more expensive tubes from the well-known manufacturers might be of higher quality and less likely to fail. Like everything else when you go generic you take the risk of getting something that?s not as good at the brand name. Other times, you luck out and you get something better.


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## Lab Worker (May 31, 2004)

nate said:


> What do the numbers for tubes mean? For instance, I have a Specialized Presta Valve Tube right here that says, "Fits 700 x 20/28C, 27 x 3/4-1 1/8." The 700 is the wheel size, so what is everything else? Will all 700mm tubes work on all 700mm wheels?


like you said, 700 is the rim size.
20 / 28 is the width range this tube will work for. It will work for a narrow 700 x 20 tire, or go as wide as a 700 x 28 tire. Anything wider than this (like a 700 x 38 tire found on a hybred bike) and the tube will not work (well, according to the mfgr anyway)

27 is another rim size...before road rims were 700mm they were 27" in "diameter." 27" tires will not fit 700c rims, or visa versa, but because tubes will stretch they will work for either size.

3/4 - 1 1/8" is the same as the 20 / 28, it signifies the width range that the tube works for.



nate said:


> What accounts for price difference between tubes, aside from weight? Is there any reason to pick a more expensive tube? Is there any reason not to get an inexpensive tube?


There will probably be debate about this. I've found that (with a few exceptions) most of the more expensive tubes have no advantages over the cheep ones. The expensive ones are most likely made in the same factory, but have more colors and fancier logos on the box, which inflates the price. (ha ha, inflates....) There are definatly exceptions to this.


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## divve (May 3, 2002)

622 also works on 700 wheels.


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## Dave_Stohler (Jan 22, 2004)

622mm *is* a 700c rim. The rim diameter is 622mm. 700 is merely an "average outer diameter" of the tire.


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## divve (May 3, 2002)

Hence, it works


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## Slip Stream (Jul 19, 2002)

Must agree Lab Worker. Expensive tubes cost more than inexpensive tubes. Sometimes expensive tubes weigh less. Conti and Michelin tubes weigh about 70-80 grams. El cheapo tubes weigh about 100-120 grams. When an expensive tube fails, a $6 tube fails. When a cheap tube fails, a $2 tube fails. If you are not racing you will probably not notice the 1/2 to 1 ounce difference. Buy tubes by in quantities of tens and invest the savings in a third tire.


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