# Bontrager tubes



## Jett (Mar 21, 2004)

I got whole mess of Bontrager tubes on sale last month. Since switching to the Bontrager tubes I've developed slow leaks in my rear tires (where I?m using the Bontrager tubes). I've tried swapping out tubes (with another Bontrager). I've double and triple checked for holes in the tube (there none). Now, these tubes do have removable values and I think they're coming loose during my rides. This is my first time dealing with removable values. Are there any tricks in keeping them airtight?


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## kjkish (Jul 15, 2005)

I have a similar problem with my Bontrager tube - I developed a leak in the inside seem near the value - I have Bontrager wheels and there are no spokes/spoke nipples near this area. My Park instant patch didn't hold so I'll be swapping the tube for a Michelin ultra light.


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## Kerry Irons (Feb 25, 2002)

*Testing*

You can check where the leak is by submerging the wheel in a tub of water once it's fully inflated (after a ride, when you think it is leaking). This will tell you if the leak is from the valve stem or somewhere else. Pinhole leaks in tubes, often at the seam in defective tubes, are very hard to find unless the tire is pumped up to full pressure.


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## Jett (Mar 21, 2004)

Kerry Irons said:


> You can check where the leak is by submerging the wheel in a tub of water once it's fully inflated (after a ride, when you think it is leaking). This will tell you if the leak is from the valve stem or somewhere else. Pinhole leaks in tubes, often at the seam in defective tubes, are very hard to find unless the tire is pumped up to full pressure.


I've run water test and didn't fine any leaks. Which is while I'm leaning toward the theory that the valve is comming loose during my ride.


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## ExtraSlow (Jul 7, 2004)

*Two blown tubes in one ride*

Maybe this is just a coincidence but I had to change two Bontrager tubes one one ride last week, after they both developed slow leaks along the seam line. This is after going the whole summer with no leaks (and using kevlar tire liners). 

I'm chalking up my experience to a bad production run -- I bought both tubes at the same time and they failed in very similar ways.

Any suggestions for other brands of tubes for large riders (250 lbs)?


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## bundokbiker (Aug 6, 2005)

*hmmm*

I wonder why these tubes are on sale? Maybe I won't buy them after all.


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## Kerry Irons (Feb 25, 2002)

*Weak theory*



Jett said:


> I've run water test and didn't fine any leaks. Which is while I'm leaning toward the theory that the valve is comming loose during my ride.


I've been riding with Presta valves since the late 60s, and have never had one come loose, on a ride or otherwise. I have had, however, what I would call intermittent leaks - a patch can come loose and behave like what you describe. At any rate, the obvious solution is to swap tubes.


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## Anti-gravity (Jul 16, 2004)

*Not so fast*



Kerry Irons said:


> I've been riding with Presta valves since the late 60s, and have never had one come loose, on a ride or otherwise. I have had, however, what I would call intermittent leaks - a patch can come loose and behave like what you describe. At any rate, the obvious solution is to swap tubes.


Don't forget about the somewhat newer presta valve tubes that have the removable valve cores. It's possible that they need to be tightened. Bontrager definitely had a run of those tubes mixed in with the ones without removeable cores. I don't know if they are using those exclusively now or not, since I don't work for a Trek dealer anymore.

Sometimes the valve cores are loose out of the box and instead are tightened tighter to the presta nut, in which case loosening the presta nut will loosen the core slightly or even completely (happened to me once with a Bonti in a tire completely inflated. The core came out along with all the air. Scared the poop out of me). I would check the valve cores and make sure they are tight. They should have flats for a 6mm wrench (or just use a small adjustable).


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## Kerry Irons (Feb 25, 2002)

*Good point*

It should be obvious that the removable cores needs to be tight! What I doubt is that if it is tight that it could loosen while riding. The standard Presta nut does not serve to keep the valve from opening - you can ride for 1000s of miles with that nut unscrewed and never lose tire pressure.


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