Tube Trouble

[JTA]

I have been "installing" my bike tubes correctly each time to the letter. However, each time the tube tears at the tube-stem junction. I have taken the suspect wheel to a shop, the rim-tape has been reseated and the tread-lip has no damage.

I have done an on-ride tube replacement and it went flat at the same spot. It is the second time inside of one hour. This is the sixth time this month it has happened.

After using a plastic tire-lever on the wheel at home, I find the tube has for some reason folded-in on itself next to the tube-stem junction.

Before I fully inflated the tube inside the rim (with the tread-lip on both sides in the rim as they should be), I made sure it was inflated just enough for proper seating.

Even though I live in a desert; the tube, tread and rim-tape had more than enough moisture in them. Dirt was not even as issue. The spokes are also NOT poking through and are properly trued.

If this little tid-bit matters, I am using the right size tube.
QTubes, Schrader Valve: 26 x 1.9 - 2.125

I am thinking the tread could be replaced or the shop I went to has a bad batch of tubes. I did not see any punctures at any point in the tread.

Suggestions?

[JohnV]

You've probably already checked this, but is the valve hole too big for the valve and are there any burrs around the hole? I can't think of anything else that you haven't already checked. Maybe someone else has had the same experience and will be able to pinpoint the problem.

[JTA]

(06-27-2011, 06:40 PM)JohnV Wrote:  You've probably already checked this, but is the valve hole too big for the valve and are there any burrs around the hole? I can't think of anything else that you haven't already checked. Maybe someone else has had the same experience and will be able to pinpoint the problem.

No problem with the hole-size and all "burrs" have been filed down.
I have had the same tire-tread since being on Oahu (hawaii), so it could be the environment-change affecting the tire.

i am also going to replace the wheel rim.

If there are any problems from a combination of the two, this should solve the problem. (It better! sheesh... all the money spent...)

The bonus of a bicycle: no pollution and it pays for itself many times over. (Yay!)

[GeorgeET]

I am confused what is this thread you are talking about?? Is it the wheel rim?? That just hold the tire in place,

As proper system I get one side of the tire on, put a bit of air in the tube so its round, not too much, put that into the tire pulling the valve through, than put the other side of tire in make sure its seated all around and that the valve is straight and pump making sure the valve does not push in.

If it keeps ripping at the hole I would reexamine the hole area and inside the rim.

[AndrewB]

On a whim, are you buying your tubes all at the same store?

Maybe try buying a tube from another store and see if the problem still happens. I wonder if you got a bunch of tubes at once and they have flaws that are impacting you.

I have ripped a couple tubes at the same point when testing pocket sized bicycle pumps due to my hands moving while pumping. Could you be moving the stem while pumping?

I assume you are also putting one or two pumps of air into the tube before you seat the tire completely.

[trevgbb]

this is valve tear off, read this;
http://www.schwalbe.co.uk/shopdata/files/TechInfo2-GB.pdf
section 25

[dave_sd]

Are they presta valves? If you overtighten the nut that secures the valve stem in the hole it can rip the valve stem out of the tube. I had this problem for a while, so I only get this nut barely finger tight