slight tear at Schrader valve base
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slight tear at Schrader valve base
Hi,
I have a slight tube tear on the base of the my valve, this is the second time this has happened, now on a new tube, any ideas why it's failing there?
Any manouveres that could cause it?
Colin
I have a slight tube tear on the base of the my valve, this is the second time this has happened, now on a new tube, any ideas why it's failing there?
Any manouveres that could cause it?
Colin
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You need to make sure that the valve is 100% perpendicular to the rim. If the valve is not straight, it will eventually tear and leak.
It may be possible to slightly round the corners of the valve hole with some fine sandpaper or a chainsaw file (or both).
It may be possible to slightly round the corners of the valve hole with some fine sandpaper or a chainsaw file (or both).
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I was getting failures on my presta valves at the base. The culprit was the air chuck that wasn't fully releasing and simply pulling on the valve stem too much as I removed the chuck. Maybe this can happen with Schrader's too if the chuck pulls a lot. But Schrader valves have a beefier boot around their base typically.
With Schrader valves, typically an issue I see is that people ride them with too little air and the tube walks (moves) inside the tire and then the stem gets pulled to an angle and slightly into the rim. So every turn of the wheel with the valve stem at an angle is working to rip that valve from the tube.
There are other things too like roughness around the hole in the rim or the hole way too big if someone did a DIY presta to schrader conversion.
With Schrader valves, typically an issue I see is that people ride them with too little air and the tube walks (moves) inside the tire and then the stem gets pulled to an angle and slightly into the rim. So every turn of the wheel with the valve stem at an angle is working to rip that valve from the tube.
There are other things too like roughness around the hole in the rim or the hole way too big if someone did a DIY presta to schrader conversion.
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I was getting failures on my presta valves at the base. The culprit was the air chuck that wasn't fully releasing and simply pulling on the valve stem too much as I removed the chuck. Maybe this can happen with Schrader's too if the chuck pulls a lot. But Schrader valves have a beefier boot around their base typically.
With Schrader valves, typically an issue I see is that people ride them with too little air and the tube walks (moves) inside the tire and then the stem gets pulled to an angle and slightly into the rim. So every turn of the wheel with the valve stem at an angle is working to rip that valve from the tube.
There are other things too like roughness around the hole in the rim or the hole way too big if someone did a DIY presta to schrader conversion.
With Schrader valves, typically an issue I see is that people ride them with too little air and the tube walks (moves) inside the tire and then the stem gets pulled to an angle and slightly into the rim. So every turn of the wheel with the valve stem at an angle is working to rip that valve from the tube.
There are other things too like roughness around the hole in the rim or the hole way too big if someone did a DIY presta to schrader conversion.
Not sure what you mean by the 'chuck'
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It can happen for a number of reasons. Either during installation of the tube, or riding with too low of pressure.
I tend to deflate my tube, and drag the fingers along the outside of the tire, going around the rim to straighten the valve (DON'T DRAG FINGERS AROUND CONTINENTAL GATORSKIN AND SIMILAR TIRES).
Some wheels seem to be fine with crooked valves, others are not which may mean it is a problem with sharp corners and burs, often exacerbated by crooked valves.
Last edited by CliffordK; 07-25-21 at 04:40 AM.
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I drill all my wheels to fit Schrader valves. can't stand presta. after drilling I debar them w/ a cpl diff. small files until they feel good to my touch, then coat the hole w/ some black paint. not sure why a wheel with an original Schrader hole would need treatment, but yeah feel it & see if it feels sharp. suppose it could be a manufacturing defect. sounds like it has been the same wheel, twice? just 2 times? how old is the bike/wheels? what brand are the wheels? wonder what brand tubes you are using, as well. & are you pumping there tires to a high enough pressure?
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If, on the other hand, it’s happening when you are using a frame pump, it may be the pump. A hand pump that you hold and pump perpendicularly to the wheel put a lot of stress on the valve. A pump with a hose like the Topeak Morph series will put less stress on the valve (and is easier to use).
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The part on the end of the pump's hose that you attach to the valve stem to fill it with air.
Many on floor pumps have a clamp lever on the air chuck to hold them onto the valve. If the clamp lever doesn't release fully or something else happens to the air chuck might be harder to pull off and might easily be enough to strain the boot on many a presta valve tube. Perhaps Schrader valves too.
Do you fill your tires with air from a compressor or something that just has an air chuck that you hold on the Schrader valve? Perhaps you push the valve stem down in the rim as you fill with air and the boot is getting damaged from that. Especially if you are bottoming out the stem on the tire. If you are pushing the stem in as you fill the tire, don't. I just used my free hand to lay a finger on the stem and rim so as to wedge the valve so it didn't get pushed in.
Many on floor pumps have a clamp lever on the air chuck to hold them onto the valve. If the clamp lever doesn't release fully or something else happens to the air chuck might be harder to pull off and might easily be enough to strain the boot on many a presta valve tube. Perhaps Schrader valves too.
Do you fill your tires with air from a compressor or something that just has an air chuck that you hold on the Schrader valve? Perhaps you push the valve stem down in the rim as you fill with air and the boot is getting damaged from that. Especially if you are bottoming out the stem on the tire. If you are pushing the stem in as you fill the tire, don't. I just used my free hand to lay a finger on the stem and rim so as to wedge the valve so it didn't get pushed in.
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I drill all my wheels to fit Schrader valves. can't stand presta. after drilling I debar them w/ a cpl diff. small files until they feel good to my touch, then coat the hole w/ some black paint. not sure why a wheel with an original Schrader hole would need treatment, but yeah feel it & see if it feels sharp. suppose it could be a manufacturing defect. sounds like it has been the same wheel, twice? just 2 times? how old is the bike/wheels? what brand are the wheels? wonder what brand tubes you are using, as well. & are you pumping there tires to a high enough pressure?
The wheel is less than a year old as is the bike, a Carbo X folding bike designed in the US.
Cannot see make on wheel, but the inner tube was 2-3 months old (second one) it had Taiwan marked on it....not sure if too low pressure has helped cause the problem.
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The part on the end of the pump's hose that you attach to the valve stem to fill it with air.
Many on floor pumps have a clamp lever on the air chuck to hold them onto the valve. If the clamp lever doesn't release fully or something else happens to the air chuck might be harder to pull off and might easily be enough to strain the boot on many a presta valve tube. Perhaps Schrader valves too.
Do you fill your tires with air from a compressor or something that just has an air chuck that you hold on the Schrader valve? Perhaps you push the valve stem down in the rim as you fill with air and the boot is getting damaged from that. Especially if you are bottoming out the stem on the tire. If you are pushing the stem in as you fill the tire, don't. I just used my free hand to lay a finger on the stem and rim so as to wedge the valve so it didn't get pushed in.
Many on floor pumps have a clamp lever on the air chuck to hold them onto the valve. If the clamp lever doesn't release fully or something else happens to the air chuck might be harder to pull off and might easily be enough to strain the boot on many a presta valve tube. Perhaps Schrader valves too.
Do you fill your tires with air from a compressor or something that just has an air chuck that you hold on the Schrader valve? Perhaps you push the valve stem down in the rim as you fill with air and the boot is getting damaged from that. Especially if you are bottoming out the stem on the tire. If you are pushing the stem in as you fill the tire, don't. I just used my free hand to lay a finger on the stem and rim so as to wedge the valve so it didn't get pushed in.
start the damage off during pumping? But I have had weeks of puncture cycling!
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What are you using to pump up the tires? If the valve is failing when using a floor pump, you may need to deburr the rim. Use a counter sink tool to chamfer the hole. Here’s a good hand one that will do the trick.
If, on the other hand, it’s happening when you are using a frame pump, it may be the pump. A hand pump that you hold and pump perpendicularly to the wheel put a lot of stress on the valve. A pump with a hose like the Topeak Morph series will put less stress on the valve (and is easier to use).
If, on the other hand, it’s happening when you are using a frame pump, it may be the pump. A hand pump that you hold and pump perpendicularly to the wheel put a lot of stress on the valve. A pump with a hose like the Topeak Morph series will put less stress on the valve (and is easier to use).
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Obviously I haven't seen your bike, but it is not uncommon to see crooked valves. These are just a couple of images taken off of the internet.
It can happen for a number of reasons. Either during installation of the tube, or riding with too low of pressure.
I tend to deflate my tube, and drag the fingers along the outside of the tire, going around the rim to straighten the valve (DON'T DRAG FINGERS AROUND CONTINENTAL GATORSKIN AND SIMILAR TIRES).
Some wheels seem to be fine with crooked valves, others are not which may mean it is a problem with sharp corners and burs, often exacerbated by crooked valves.
It can happen for a number of reasons. Either during installation of the tube, or riding with too low of pressure.
I tend to deflate my tube, and drag the fingers along the outside of the tire, going around the rim to straighten the valve (DON'T DRAG FINGERS AROUND CONTINENTAL GATORSKIN AND SIMILAR TIRES).
Some wheels seem to be fine with crooked valves, others are not which may mean it is a problem with sharp corners and burs, often exacerbated by crooked valves.
I will look at deburring also.
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Stressing the valve seat doesn’t necessarily result in an instant flat but it can start the process. Tubes and tires can creep while riding, especially if the tire is going flat slowly. If you have stressed the valve seat while pumping up the tire, it can tear the valve stem later while riding.
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Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
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