700 X 25C tube

You should probably be okay, if it is a quality tube. Tubes are certainly commonly made to accomodate 700x25C. Different manufacturers, however, will have slightly different ranges that they specify for the various tube sizes. For example, Continental breaks it up at 18-25, 28-37, etc. Michelin goes 18-23, 25-32; Nashbar's house brands are listed as 19-26, 28-32, etc. If you are using ultralight tubes or such, I would be a little more concerned.

Go Conti: http://www.conti-online.com/generator/www/de/en/continental/bicycle/themes/tires/tubes/tubes_en.html 😄

rdk said:

Went into my LBS the other day to get a tube for my 700 x 25C wheels. He said they don't make them that size (!), and sold me tube with "fits 19/23mm tyres" on the box. He said it will stretch just fine - is this true? I'm sure I've purchased previously 25/28mm tubes.

That won't be a problem at all, there's hardly any difference.

I have run 700x19/23mm tubes in 700x38 (yes, 38) tyres for months on end without any hassle. The only thing you need to be aware of is that because the tube stretches out a bit more, the rubber is thinner.. which means that all else being equal, you are at a slightly higher risk of getting a puncture. (I never got any though)

Provided you keep to an air pressure appropriate for your tyre size, there will be little chance of a blowout.

Went for a ride today and everything A-OK. The LBS was definitely wrong though, as in my shed I actually found a 25/28mm tube I had as a spare made by the same company (Vittoria). Beginnings of Alzheimers I think. The original "they don't make 25 mm tubes" from the shop came from a LBS I had previously paised to high heaven in these forums.

I used to put tubes that were labeled 27" X 1 1/8" to 1 1/4" inside 700 X 45 mm tires, which are quite wider and aren't even the same diameter. Now I have 700 X 25 mm tires and put the same tubes in them. Tubes do expand to fit the tire and as long as you use road tubes on road bikes or 700 mm hybrid bikes, and MTB tubes on mountain bikes then you should be OK.