flat question
03-29-09, 04:47 PM
#1
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flat question
So I finished a 52 mile ride yesterday on some really crappy roads and realized that my tire was extremely low. I replaced it today and after a few minutes of searching the tube, I finally found the culprit. It was a very tiny hole near the base of the valve stem. The tube was just put in last weekend, after getting a flat.
The hole seemed to be in an odd spot, so my question is, could the tube be defective or is it possible to get a flat that close to the stem? If it's any help, I do have the little washers around the valve stems. I've just always kept them on there.
Thanks for any advice.
The hole seemed to be in an odd spot, so my question is, could the tube be defective or is it possible to get a flat that close to the stem? If it's any help, I do have the little washers around the valve stems. I've just always kept them on there.
Thanks for any advice.
03-29-09, 04:55 PM
#2
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Some holes and flats are a complete mystery.
Some like yours come from pinching during installation.
Some like yours come from pinching during installation.
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Fred "The Real Fred"
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03-29-09, 05:57 PM
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Tears at the base of Presta valve tubes are common. Typical causes are flexing the valve too much during the inflation process and over tightening those little valve stem nuts.
03-29-09, 06:02 PM
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Is there any specific time when I really need to look out for pinching? I mean, is there a specific step in the process where it's more likely to occur?
I'll also watching it with those stem nuts. I thought that and the fact that I was riding over some terrible roads might have had something to do with it.
Thanks.
I'll also watching it with those stem nuts. I thought that and the fact that I was riding over some terrible roads might have had something to do with it.
Thanks.
03-29-09, 09:51 PM
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Folds, pinches, etc are hard to check for as you would need to be able to see the tube, thus removing the tire. Kinda counter productive. What is better is to start the tube with a bit of air in it, just enough to give it some shape. This will help avoid in folds, pinches, etc.
03-30-09, 11:35 AM
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I have seen such holes near the base of the stem that were definitely defects. Identical tubes right out of the box had the exact same holes as the one that went flat.
Al
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03-30-09, 11:43 AM
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I recommend pitching the stem nut altogether... it's not really needed.
03-30-09, 03:23 PM
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I would bet that 95% of the time, holes near the valve stem are caused by using a small frame or minipump and flexing the stem to the point of breaking. A basic floor pump kept at home and the minipump used only in emergencies is the ideal setup.
03-30-09, 05:05 PM
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Those types of holes can also come from pulling the tube thru the rimhole while removing the pump chuck.
