# Tire/tube size



## KellyMo

First off, I think this is my real first newbie post... I've been trying to find a topic that hasn't already been answered for quite a while ( :thumbsup: ), and now I think I've finally found something.

1) Just got a road bike. The sides of my tires say 23 - 622 (700 x 23C). From other posts, I gather that the width of the tire is [supposedly] 23mm. What do the 622 and 700 mean? Does the 'C' mean anything of importance?

Nashbar.com is a bit confusing; the [viable] options for tubes that size are as follows:
700x18/20-36MM VALVE (1)
700x18/23c (1)
700X19-25 PRESTA (1)
700x19/23-51MM VALVE (1)
700x19/23-PRESTA VALVE (1)
700x22/23-36MM VALVE (1)

I know I want presta, but that selection is a bit confusing (and that's not even the weird sizes I don't think apply).
2) What's a 36 or 51mm valve? 3) Why are the presta valves so friggin long (42cm???)? 

I'm going to just trek over to a lbs and get something there, but what does all this mean? 

Thanks in advance.


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## Arginine

700 is the size of the wheel (some smaller road bikes have 650 wheels). Presta valves come in a variety of lengths to accommodate deeper wheels (especially deep dish carbon wheels).


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## kfurrow

KellyMo said:


> Just got a road bike. The sides of my tires say 23 - 622 (700 x 23C). From other posts, I gather that the width of the tire is [supposedly] 23mm. What do the 622 and 700 mean? Does the 'C' mean anything of importance?


As you guessed, the "23" is the (supposed) width of the tire. As for the "622" and "700C" parts -- http://www.sheldonbrown.com/tyre-sizing.html. More then you could ever want to know.



KellyMo said:


> Nashbar.com is a bit confusing; the [viable] options for tubes that size are as follows:
> 700x18/20-36MM VALVE (1)
> 700x18/23c (1)
> 700X19-25 PRESTA (1)
> 700x19/23-51MM VALVE (1)
> 700x19/23-PRESTA VALVE (1)
> 700x22/23-36MM VALVE (1)


The x/y part (i.e., 18/23) is the range of tire sizes that tube will worth with. You can put smaller tubes into larger tires, to a point. i.e., your first example (700x18/20) would work fine with a 700x23 tire, even though the tire is listed as "too big" for the tube.

The valve stem length is for different rims; deep-dish "aero" rims need longer valve stems or there's nothing to get the pump onto. A 36mm valve stem is pretty short; I use those on older 32-spoke wheels (i.e., the kind that don't get sold with new bikes anymore). A mid-40's length valve stem works with most "common" wheels. You can use a much longer valve stem then is physically required; it just sticks up a long ways and winds up looking somewhat ridiculous.


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## Cory

What everybody else said, plus this: The first number, the 700, is critical, but you don't have to worry much about the second one, the 23 or whatever. I've bought one size of road tubes for years, 700x25, and use it in tires from 23 to 41mm wide. No problems ever. Handy if you have more than one bike and they're set up differently.


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## KellyMo

kfurrow said:


> http://www.sheldonbrown.com/tyre-sizing.html. More then you could ever want to know.


That's what I wanted to know!

Thanks all for the replies. I feel adequately educated now.


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