Is this tube defective?

[niltohams]

I've never seen a tube that looks like this before. It has some air in it. It caught a flat on the side opposite the stem, so it's not holding a lot of air for long. I wonder if it's because of the weird shape. The circumference of the tube at the valve is definitely much narrower than the rest of the tube. The tube with which I replaced it, a different brand, looks fine: perfectly round.

 

[BarryS]

I've never seen a tube that looks like this before. It has some air in it. It caught a flat on the side opposite the stem, so it's not holding a lot of air for long. I wonder if it's because of the weird shape. The circumference of the tube at the valve is definitely much narrower than the rest of the tube. The tube with which I replaced it, a different brand, looks fine: perfectly round.

View attachment 61620

From what you are showing us and Stating I would say Yeah : Especially if it's leaking opposite the valve : Makes it rather obvious

 

[harryS]

I've had three flats awat from home in the last few weeks, so I've seen three inner tubes. One appeared symmetrical, but the other two were like animal ballons, both skinny and fat in different sections. I re-use them if they hold air.

Nome of the flats were due to road hazards. All user error. One was underinflated, and the tire slipped and cut a hole in the valve stem. The second was overinflated, of course, and a sharp corner on the rim worked its way thru the rim tape, The last one must have been me not screwing the core all the way back in on a Presta valve. No hole detected with the underwater bubble test.

 

[rich c]

Nothing wrong with the tube when it has a shape like that. It just stretches out and fills the tire. Maybe just a little harder to put a patch on it.

 

[Nova Haibike]

Deviation in manufacture. It is not ideal, but it is relatively common and in practice it makes no difference. As rich c says, when you inflate the installed tube, it just stretches to fill the tire.

 

[tomjasz]

a hole in the valve stem.

I transitioned to all "Conti" steel stemmed tubes with lock nuts and find their tubes to be consistent. I also take down every rim and use thick VELOX fabric rim tape. Bob's me uncle!