Which size tube for 35mm hybrid tyres?

[RoadRider400]

Tubes I want to buy are either 28-35 or 35-45. Im guessing its the smaller one. Is that right?

 

[vickster]

Yep

 

[raleighnut]

^^^^^^^ +1, easier to get into the tyre than the fatter option.

 

[I like Skol]

Either will do.

 

[andrew_s]

I'd go for the fatter option.

The tube is less stretched, so when you do puncture the leak is slower.
It gives you chance to stop before the tube is completely flat (failure to do which can result in a snakebite puncture in addition to the original), and thorns can plug the hole in an unstretched tube well enough that you can ride 2 or 3 days before it goes flat.

 

[Cycleops]

Either, I’d go with the bigger one As above.

 

[Ajax Bay]

Given a preference, I would choose the 28-35 option for the reason @raleighnut shared and because the larger tube offers no benefit and has a greater risk of getting pinched (if on a tight rim) during fitting.

the fatter option . . . tube is less stretched, so when you do puncture the leak is slower.

The permeability (to air) of a tube with thicker walls is less, but that's not the puncturing mechanism.
Andrew - besides the fact that most punctures are not 'slow' ones (citation needed) - why do you think that a hole through a 'less stretched' tube will leak air more slowly - whence do you draw that assertion, please? Or are you relying on intuition?

 

[Vantage]

A hole in the tube is a hole in the tube regardless of its size and the speed at which it allows air to escape. Not to mention the chances of hitting the exact same puncture causing implement in the exact same circumstances with 2 differently sized tubes are somewhat low so saying one will leak faster than the other is a bit of a weak point. You could get a puncture in the smaller tube rolling across a pin then get another puncture in the bigger tube slamming the tyre into a stray machete.
I'd go with the smaller tube as per others here. It'll be much easier to fit into the tyre.

 

[andrew_s]

Andrew - besides the fact that most punctures are not 'slow' ones (citation needed) - why do you think that a hole through a 'less stretched' tube will leak air more slowly - whence do you draw that assertion, please? Or are you relying on intuition?

If there's a hole in a stretched tube, the rubber just next to the hole will pull away from the hole, because the rubber on the other side of the hole that was previously holding it in position is no longer doing so. Because the rubber has pulled away from the hole, the hole is bigger, and the air comes out faster, until enough has leaked out that the tube is no longer stretched.
You can easily see what happens if you cut half way through a rubber band (width ways), and then stretch it.

The fact that stretched tubes leak faster is also useful when trying to find the hole in a punctured tube. If you don't find the hole at first, just pump the tube some more, until it's stretched enough to leak fast enough that finding the hole is easy. Buckets of water not required (but a decent pump is, with "decent" excluding all mini-pumps).

I would estimate that about 20-25% of my punctures are "slow". That is, I leave the bike, having arrived, and come back later to find the tyre flat, or I notice a soft tyre, give it a pump, and get several miles before it's soft again. In some cases "several miles" might be over 100.
The slow puncture causes are usually thorns, but can also be things like strands of wire, or small fragments of flint or glass that don't protrude far enough inside the casing to cause an instant puncture, but will nibble their way through in due course.

 

[Tigerbiten]

I tend to go for the bigger size.
The less you stretch the rubber, the more likely a slow puncture remains slow.
I also find it's easier to repair it on the road if you've run out of spare tubes if the inner tubes on the bigger size.
If you put a little air in the tube before fitting it then it's easy to avoid catching it as the last of the tyre goes over the rim no matter its size.

Luck ...........

 

[RoadRider400]

Thanks for all the input everybody. I didnt expect such a detailed debate. I was going to get 2 inners so I might as well get one of each seeing as its a draw with the judges.

 

[I like Skol]

I would get the bigger, thicker tubes personally. Have said the same in the past then faced the same factless ridicule for it so decided not to bother this time

 

[Ajax Bay]

"Factless ridicule". Please share examples. It's only a b****y tube fgs. The slightly larger diameter one will be fine, of course, but the OP asked which one. People above have offered their opinion (CycleChat); some have explained on what basis they prefer one to the other.

I was going to get 2 inners so I might as well get one of each seeing as its a draw with the judges.

Good call. Let us know if you think the difference makes a difference.