700 28-38 or 20-28

[maddog.mark]

So which is best if you have a 700 28 tyre? Having just blown up a 28-38 as I inflated it, must have pinched it and not noticed I'm inclined to go for a 20-28 but would appreciate any views on the pros and cons if there are any.

Thanks and seasons greetings

Mark

 

[andrew_s]

Are we talking inner tubes?
Compared to 20-28, 28-38 will be more puncture resistant, but heavier and more prone to getting trapped under the bead.

 

[maddog.mark]

Are we talking inner tubes?
Compared to 20-28, 28-38 will be more puncture resistant, but heavier and more prone to getting trapped under the bead.

Sorry yes we are. I was putting some Armadillo tyres on which should be puncture resistant so I guess the 20-28 should be ok then.

thanks for your response

 

[Banjo]

Sorry yes we are. I was putting some Armadillo tyres on which should be puncture resistant so I guess the 20-28 should be ok then.

thanks for your response

And take up less room in your bag.

 

[Alien8]

Are we talking inner tubes?
Compared to 20-28, 28-38 will be more puncture resistant

Why's that then?

Unless an inner tube has Slime or suchlike in it I would image they have approximately zero puncture resistance regardless of size.

 

[GrasB]

Sorry yes we are. I was putting some Armadillo tyres on which should be puncture resistant so I guess the 20-28 should be ok then.

thanks for your response

the Spesh 700x28c All Condition Armadillos came supplied with 700x20-28 innertubes.

 

[maddog.mark]

the Spesh 700x28c All Condition Armadillos came supplied with 700x20-28 innertubes.

Mine didn't but my 20-28c arrived today and have been fitted to the bike without further explosions!
thanks for the comments all

 

[andrew_s]

Why's that then?

Unless an inner tube has Slime or suchlike in it I would image they have approximately zero puncture resistance regardless of size.

Smaller tubes are stretched more, and much easier to damage than a comparatively unstretched tube. Try cutting a rubber sheet or a bit of old tube with a knife.

examples...

You may have something inside the tyre, like a bit of grit, split rim tape or an exposed spoke hole.
A fragment of glass may have just the very tip getting through the tyre. A small tube will puncture straight away, but a big one may last long enough to show up as a slow puncture that you can fix at home.
A thorn may plug the hole it's just made. I've ridden for over a month with a slow puncture (pump up every other ride) that turned out to be a thorn that had gone a centimetre through the tyre