Tires

stanhill

I have 700x30 tyres on my new byke. What size inner tube do I use. I am new to this size of tyre.
Mike

imposter2.0

Ideally, a tube with a width between 28-32...

stanhill

Thanks for the reply

N0bodyOfTheGoat

The actual width of a tyre can vary from claimed width, depending upon manufacturer and specific model. For instance, 700x28 Continental GP4000S II typically measure ~31mm wide. A 28mm inner tube would work, but might be stretched a bit more, which could possibly explain why my 28mm latex tubes inside said tyres lost pressure (~15PSI) over a couple of hours or so when initially inflated to ~95PSI.

super_davo

If you inflate an inner tube outside a tyre you'll see how much it stretches; net result is the sizing isn't that critical (as long as it is 700C)

For a 30mm tyre I'm sure you'd be able to get away with 18/23 mm width if you had to; I do on 28mm tyres on 19mm internal rims. Tubes rated for 28mm would be peachy.

Latex tubes lose pressure really quickly whatever, I could definitely see the effect becoming worse if the tube was more stretched in a larger tyre though. Shouldn't be an issue with normal Butyl tubes though.

airborneal

Expect your sorted now but something like below would be ok. Just make sure you get the correct valve whether it is Presta or Schrader and that the valve is long enough. Personally I wouldn't recommend going too narrow [18/23mm], yes they will expand but all the time the thickness of the rubber is getting thinner.
https://www.planetx.co.uk/i/q/TUVILIRO/ ... inner-tube

stanhill

Thankyou. Any inforrmation is useful.

svetty

airborneal wrote:

but all the time the thickness of the rubber is getting thinner

Surely that's a good thing. As long as the tyre is supporting the tube the thinner layer will mean a better ride and lower rolling resistance.