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Old 09-15-10, 07:34 PM   #1
andrewsitompul
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Presta Valve VS Schrader Valve

I just noticed today that my tire needs a little air, when i tried to inflate it i notice that it's not your regular valve, when to my local bike shop, they told me what i have is called "presta valve". What is the benefit of having this valve?? and can i go back to the regular valve (schrader valve)?
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Old 09-15-10, 07:54 PM   #2
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Presta: Primary the smaller hole in the rim, which makes the rim stronger... it's also a bit easier to pump up since the nut can prevent the valve from prairie doggin' in the rim.
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Old 09-15-10, 07:55 PM   #3
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Presta valves dont require as large hole in the rim as Schrader valves. Presta pumps can be made without a check valve which makes the lighter and more reliable (today most frame pumps are convertible so they don't take advantage of this). Converting to schrader requires that your rim be drilled to accept the larger valve, depending on your rim this may weaken it. You can always put an adapter on that will let you fill your tires with a Schrader pump.
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Old 09-15-10, 07:55 PM   #4
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Chances are that the hole in your rim is not big enough for a Schrader valve.
Presta valves seem normal to me.

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Old 09-15-10, 07:57 PM   #5
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The presta valve is "regular" for high-pressure low-volume applications like narrow wheelchair and bicycle tires. The advantage is that the valve only opens when the pump is putting air into it. The pump pressure opens the valve, and when pressure is absent, the valve closes. You can achieve higher pressures with a hand pump that way. With a schrader valve, the valve opens when the pump head engages with it, so the pump is always at the same pressure as the tube. This makes it very hard to reach and maintain high pressures with a manual pump. Presta valves also happen to be smaller in diameter than schraders, making them more suitable to narrow rims; a smaller valve hole means less compromise of the rim's structural strength.
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Old 09-15-10, 10:43 PM   #6
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Usually what kind of bikes have Presta valves? Or is it random?
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Old 09-15-10, 11:18 PM   #7
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Presta valves main reason for success is due to the fact that they are easier to pump higher pressures of air into the valve because their is no valve spring to overcome as is with the Schrader.

The nut does help prevent the Presta valve from receding into the rim when attempting to pump a flat tire...BUT...I never used those nuts in over 35 years of using Presta valves! I simply hold my mini pump with 4 fingers at the base and loop my thumb over the rim and around the tire and hold press the tire into the rim (with the thumb) and pump, doing it this way also helps keep the valve straight while pumping so you don't accidentally tear off the valve or bend the valve core.

Along with that, as Electrik said it makes the rim stronger.

As a side note, you also do not need to use the plastic cap to put over the valve core nut like you do with the Schrader because when you tighten (just snug, not real tight) down the knurled little barrel nut serves as a cap, but I use the cap anyway so the little barrel nut doesn't accidentally get bent. I've had them get bent and not even know why, but a slight bend can make the valve useless, and bending it back sometime breaks it.


Schrader valves are sturdier though.
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Old 09-15-10, 11:23 PM   #8
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no its not random ..
Schrader on Low pressure tires , MTBs, for the Lumpen Prolo's and the bottom of the price-range.
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Old 09-16-10, 11:03 PM   #9
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no its not random ..
Schrader on Low pressure tires , MTBs, for the Lumpen Prolo's and the bottom of the price-range.
Actually Schrader valves are used daily in applications upwards to 15,000 PSI. So no, their not limited to low pressure. And 747 jumbo jets require 175 to 180psi on the nose tires and 200 to 205 on the main gear...and they use Schrader. And once, for a unrelated experiment, I put 210 psi in a MTB tire and Schrader held just fine...I was more worried about the rim and tire, the valve wasn't even a remote concern.
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Old 09-16-10, 11:14 PM   #10
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Presta valves are easier to fill and easier to take a smidge air out of when I need more traction in the winter.

Schrader = Pffft.
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Old 09-16-10, 11:22 PM   #11
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Actually Schrader valves are used daily in applications upwards to 15,000 PSI. So no, their not limited to low pressure. And 747 jumbo jets require 175 to 180psi on the nose tires and 200 to 205 on the main gear...and they use Schrader. And once, for a unrelated experiment, I put 210 psi in a MTB tire and Schrader held just fine...I was more worried about the rim and tire, the valve wasn't even a remote concern.
But airplane landing gear doesn't have in its design requirements the ability to be inflated with a frame pump.
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Old 09-16-10, 11:53 PM   #12
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But airplane landing gear doesn't have in its design requirements the ability to be inflated with a frame pump.
That's been irrelevant since the mid-70s when Zefal came out with their thumb-lock design for their frame pumps. Ever since then it has been equally easy to inflate the two valve types by hand. And the rim strength argument is also irrelevant except possibly for the very narrowest rims. I've drilled out quite a few rims to allow Schrader valves to fit and not one has ever failed at the valve hole. Rims fail at the braking track and at spoke holes - valve hole failures are really rare. The final argument raised has been about the nut on threaded Presta valves. But note that 1) many people avoid the use of this nut even when available, and 2) lots of Presta valve stems are smooth on the outside and don't include this nut.

At this point I think the continued popularity of Presta valves is more one of fashion than anything else. Light road bikes have traditionally used Presta valves and so they continue to do so. And they are marginally lighter than Schrader.
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Old 09-17-10, 10:00 AM   #13
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That's been irrelevant since the mid-70s when Zefal came out with their thumb-lock design for their frame pumps. Ever since then it has been equally easy to inflate the two valve types by hand. And the rim strength argument is also irrelevant except possibly for the very narrowest rims. I've drilled out quite a few rims to allow Schrader valves to fit and not one has ever failed at the valve hole. Rims fail at the braking track and at spoke holes - valve hole failures are really rare. The final argument raised has been about the nut on threaded Presta valves. But note that 1) many people avoid the use of this nut even when available, and 2) lots of Presta valve stems are smooth on the outside and don't include this nut.

At this point I think the continued popularity of Presta valves is more one of fashion than anything else. Light road bikes have traditionally used Presta valves and so they continue to do so. And they are marginally lighter than Schrader.

This is true to a point. Older generation of rims where not as good as the ones today and suffered from cracks and thus the Presta valve was developed. But presta valves are also lighter then schrader and roadies are mostly weight weenies and would cringe have to use a big bulky heavy schrader valve. So it's a little more then just fashion, but fashion is part of it. I never use the nut as I said earlier, and my current tubes didn't even come with one because the shaft is smooth.
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Old 09-17-10, 04:06 PM   #14
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At this point I think the continued popularity of Presta valves is more one of fashion than anything else. Light road bikes have traditionally used Presta valves and so they continue to do so. And they are marginally lighter than Schrader.
Not fashion but function. Presta valves are held shut by the pressure inside the tire/tube. To fill them, you only need to overcome that internal pressure by a small amount to open the valve. Any air that goes into the tube stays there. When you release the pump head, there is absolutely no leakage from the tube so the pressure inside the tube can be accurately read and maintained.

With a schrader valve, the valve has to be opened, and held open, to put air in it. If the pump head is improperly sealed on the valve stem, you can...and often do...lose air from from the tire/tube. If the point is to add air to the tire, why would you want to lose any to begin with? The seal around the stem is much more critical for schrader, too. Even with a good seal, there is going to be some pressure release when the pump head is removed.

There is also an issue...a slight one but it's still relevant...of damage. Schrader valves are much more prone to cuts from the valve hole than prestas are. Especially in low pressure situations. On a mountain bike, for example, the high torque and low pressure can lead to tube creep. If the rubber covered schrader valve creeps too far, it can cut the stem. Prestas can't suffer stem cuts in the same manner. The little nut on presta valves, by the way, helps prevent creep in those kinds of applications. Presta valves can be damaged from the pressure pushing the stem out of the rim but schraders can also suffer from this kind of damage.
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Old 09-17-10, 04:16 PM   #15
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Go to the LBS and ask for a Presta-Schrader adapter.
Probably cost a buck or two.
Then you can use any Schrader pump.
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Old 09-17-10, 06:42 PM   #16
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Not fashion but function. Presta valves are held shut by the pressure inside the tire/tube. To fill them, you only need to overcome that internal pressure by a small amount to open the valve. Any air that goes into the tube stays there. When you release the pump head, there is absolutely no leakage from the tube so the pressure inside the tube can be accurately read and maintained.

With a schrader valve, the valve has to be opened, and held open, to put air in it. If the pump head is improperly sealed on the valve stem, you can...and often do...lose air from from the tire/tube. If the point is to add air to the tire, why would you want to lose any to begin with?
True in principle, but as I stated above, this has been a non-issue ever since Zefal introduced their thumb-lock HP frame pump around 1976. It and similar pumps by others since then seal around the top of the valve just before depressing the little pin in the Schrader valve so the only air lost is a few ml that go into the very end of the pump - maybe you lose 0.1 psi before you start pumping. This used to be a big problem back when the Schader pin was depressed by a knob inside the tube you had to screw down onto the valve. You'd be frantically unscrewing the tube with the air hissing out and hoping you wouldn't lose too much pressure. With frame pumps designed in the last few decades this is a non-issue. Now there is far more air lost from the Presta valve since those frequently need to have the valve opened a bit manually before using a pump to avoid having the valve stick closed and refuse to let in any air from the pump.
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There is also an issue...a slight one but it's still relevant...of damage. Schrader valves are much more prone to cuts from the valve hole than prestas are. Especially in low pressure situations. On a mountain bike, for example, the high torque and low pressure can lead to tube creep. If the rubber covered schrader valve creeps too far, it can cut the stem. Prestas can't suffer stem cuts in the same manner. The little nut on presta valves, by the way, helps prevent creep in those kinds of applications. Presta valves can be damaged from the pressure pushing the stem out of the rim but schraders can also suffer from this kind of damage.
Again, possible in principle, but I have yet to see a cyclist have this problem with a Schrader valve while I have seen quite a few Presta valve failures when they either bent the valve while pumping or had it pull out of the tube when removing their pump. The creep issue doesn't arise at the tire pressures that I use on my bikes. The Schrader valves appear to be considerably more durable and less subject to damage from abuse while pumping.
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Old 09-17-10, 09:28 PM   #17
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There is also an issue...a slight one but it's still relevant...of damage. Schrader valves are much more prone to cuts from the valve hole than prestas are. Especially in low pressure situations. On a mountain bike, for example, the high torque and low pressure can lead to tube creep. If the rubber covered schrader valve creeps too far, it can cut the stem. Prestas can't suffer stem cuts in the same manner. The little nut on presta valves, by the way, helps prevent creep in those kinds of applications. Presta valves can be damaged from the pressure pushing the stem out of the rim but schraders can also suffer from this kind of damage.
Really? I've never heard of this about schrader's unless the tire is flat. If this were true then all the MTB racers would be using presta. And I've had presta valved tubes pushing 130psi without using the nut and never had a stem "push" it's way out of a rim, and what about tubulars pushing 200psi using prestas? Nor I have I heard of schrader doing the same thing. All damage I've seen from Presta valves was due to operator air; I will admit that shraders are less likely to get damaged due to operator error but it could happen.
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Old 09-18-10, 04:57 PM   #18
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I love these threads.

I love reading the people who make monumental mountains out of miscule molehills. Usually somebody says something about presta valves holding air pressure better but that's already been de-bunked.

To me, Presta wins the "smaller hole in the rim is stronger" points. On the other hand, I've never seen a rim fail at the valve hole.

Schrader wins, by a mile, the valve stem tearing battle. If you're getting enough tire creep to cut a Schrader valve, a presta valve stem is going to tear loose from the inner tube. And frankly, I think that little nut causes lots more tube damage than it prevents.

Difficulty to inflate in the real world is a Presta win by a nose if you are using a hand pump and a Schrader win by a mile if you have an air compressor.
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Old 09-18-10, 06:06 PM   #19
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Now there is far more air lost from the Presta valve since those frequently need to have the valve opened a bit manually before using a pump to avoid having the valve stick closed and refuse to let in any air from the pump.

Again, possible in principle, but I have yet to see a cyclist have this problem with a Schrader valve while I have seen quite a few Presta valve failures when they either bent the valve while pumping or had it pull out of the tube when removing their pump. The creep issue doesn't arise at the tire pressures that I use on my bikes. The Schrader valves appear to be considerably more durable and less subject to damage from abuse while pumping.

Wrong, wrong, wrong. You don't understand the presta design. It's normal to tap the top to free-up the seal before trying to add air to a tire. If you don't it may take 150 psi just to break the seal. That is normal. There is ZERO air lost with a presta because the valve seals as soon as the pump pressure is the same as the what's in the tire. When you remove a presta head, all of the escaping air is in the pump.
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Old 09-18-10, 06:42 PM   #20
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To the OP, if there is a small black plastic rim around the base of the valve, then you can take that out and use a Schraeder ( car type ) valve. If not, you can drill out ( carefully ) the rim to accept the Schraeder, or get an adapter that will let you top up at a compressor.

Anyway, you should have a floor pump at home, they're not expensive, and they almost always do both types of valve.
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Old 09-18-10, 07:10 PM   #21
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Wrong, wrong, wrong. You don't understand the presta design. It's normal to tap the top to free-up the seal before trying to add air to a tire. If you don't it may take 150 psi just to break the seal. That is normal. There is ZERO air lost with a presta because the valve seals as soon as the pump pressure is the same as the what's in the tire. When you remove a presta head, all of the escaping air is in the pump.
Oh, I think I understand the Presta design just fine and have been using the things for the last 40 years.

But 'cycocommute' indicated that a problem with Schrader valves was "If the point is to add air to the tire, why would you want to lose any to begin with?" i.e. the tiny amount of air lost when first putting the pump head on the valve. Since that air loss is minimal compared to the amount lost when tapping the Presta valve to avoid the sticky seal issue this is a net win for the Schrader design - not that it's a big deal for either valve type. Yes, it is normal - but it still results in a loss of some air.

And sure, the Presta valve doesn't lose air when the pump is disconnected, but the point was that this is also essentially true for Schrader valves as long as you're using a decent pump designed sometime after the mid-70s. The head is designed so the pin in the valve is released thus sealing the tube simultaneous with or just before the seal to the pump head is broken, so there's no significant air loss at disconnection with either valve design.
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Old 09-18-10, 07:21 PM   #22
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I use both valves (not only have I used both valves about equally on several different bikes, over the last several years, the bike I currently ride has schrader on the back wheel and presta on the front) and I favor schrader. Schrader seems to be more "robust", I've torn a few presta valves near the stem which taught me to be more gentle with them (and to pull straight up more-so than side-to-side when disconnecting the pump-head). My schrader valve instantly blows the pump head (of my floor pump) off when I flip the engage/disengage lever when disconnecting. Disconnecting from presta takes a little tugging (my presta valves are not smooth on the sides so that may contribute to this slight stubborness to disconnect). The pumps I use have dual heads (one hole for schrader, another hole for presta) and I don't notice an obvious difference when pumping my tires to 100 + psi (at least that is what the gauge on my pump reads), I'm not saying there is no difference, just that I don't notice an obvious one.

Though I favor schrader, I don't plan on having my presta rims altered for schrader, it's not THAT big of a deal to use presta, I just handle presta valves more delicately. I carry a presta-to-schrader adapter in my flat-repair kit to keep my options open (like using gas-station air) but have never used it (since my floor-pump and mini/portable pump both have dual-heads). I have fine-tuned my mini-pump technique with presta so that I don't tear the valve-stems out (I never got around to getting one of the mini-pumps with the hose included, like a Topeak road morph, which would be cool to have).
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Old 09-18-10, 08:06 PM   #23
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I also use both. Presta on my bikes, Schrader on my car.
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Old 09-18-10, 09:02 PM   #24
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Oh, I think I understand the Presta design just fine and have been using the things for the last 40 years.

Since that air loss is minimal compared to the amount lost when tapping the Presta valve to avoid the sticky seal issue this is a net win for the Schrader design - not that it's a big deal for either valve type. Yes, it is normal - but it still results in a loss of some air.


.
Well that comment right there told me all I needed to know about your experience in the last 40 years with Presta valves. All you need to do is just a quick very short air burp that at the most will lose 1/2 to 1 pound of air psi at the most.

If you really want to learn something then read this from Jobst Brandt, google him if you want to know who he is, read this site in it's entirety unless you just want to set there and pretend you know something you know nothing about.

http://yarchive.net/bike/presta.html
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Old 09-19-10, 08:37 AM   #25
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Well that comment right there told me all I needed to know about your experience in the last 40 years with Presta valves. All you need to do is just a quick very short air burp that at the most will lose 1/2 to 1 pound of air psi at the most.
As I said - it's not a big deal with either valve type. But that short air burp from the Presta valve is still a loss of much more air than I get when putting the head of any decent thumb-lock pump on a Schrader valve.

I agree with Jobst's comments, but the two advantages he cites for Presta have lost their practical significance for all but the very narrowest of rims.
The first is the supposed weakening of the rim due to the larger hole. True in principle, but I've never seen a rim fail at the valve hole - and that includes narrow rims made for 23 mm tires that have been reamed out enough to fit Schrader valves. Even with the larger hole, that area is still strong enough to last for the life of the rim before it fails from other problems - typically due to thinning of the brake surface or cracks at the spoke holes.

The second is that you can use a simpler pump since you don't need to include a check valve. Again, a true statement, but not relevant in practice since almost all frame pumps are now made to accommodate both types of valve so you get the check valve in the pump whether or not you need it. The old Silca pumps were very simple mechanically and only work with Presta valves, but I don't see many of them around anymore because pumps by Zefal, Topeak, and Lezyne work better (and these all include the check valve and are equally easy to use with either valve type).
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