Bike pump hissing during inflation (beginner question)

**zia** · 10-19-2009, 07:13 AM

I have presta valves. I am inflation impaired. Followed this web site on how to inflate them: http://bicyclesouth.com/change_tire.htm

I think, however, their picture of the floor pump being in the "up" position is incorrect -- it's in the "down"... right? "Down" should mean the value is parallel to the hose tube, and "up" is perpendicular. I think.

So I set up my floor pump, attach it to the presta valve, flip to the "up" (valve perpendicular to hose tube) position. Lots of hissing. Pump furiously to get more air into the tire than is comes out. Repeat on other wheel.

How do I get the hissing to stop while I'm pumping? Holding the hose head to the valve helps... a little. But makes for awkward pumping. And I never can seem to "fully" inflate my tires.

Argh!

**OakLeaf** · 10-19-2009, 07:27 AM

After you unscrew the valve stem, tap it gently to break the seal. Then make sure your pump head is fully seated and straight on the valve. Depending on the pump, that might take a little finagling. Personally, I think it's easier to have the valve stem at 12:00 rather than at 6:00 as pictured. Then if you need to, you can hold it with one hand while pumping the first 1-2 strokes with the other.

Both my pumps lock by pulling the lever inline with the valve, perpendicular to the hose. If you're not sure, you can check by looking at the pump head while pulling the valve. You'll see the rubber gasket compress when it's in the locked position.

If you're hearing all that hissing, chances are air isn't going into your tires at all. Worst case, deflate your tires until they're moderately soft but not flat. That'll make it easier to break the seal and get the pump head seated.

**zia** · 10-19-2009, 06:39 PM

OakLeaf to my rescue again! My valves actually look a little crooked and bent - maybe that's part of the problem. It would be good practice for me to change the tubes anyway.

I will try again using your extra tips...

**lph** · 10-19-2009, 09:38 PM

I hate presta valves. I have used both for a long time now, and I never have as much trouble with the schrader valves. I especially hate inflating completely empty tubes with presta valves, but the trick I read somewhere of inflating it by mouth first helps. Maybe my pump is the culprit, I dunno. I think pumps lock down in different ways by the way, depending on the type.

**channlluv** · 10-20-2009, 01:06 AM

When I had to get a new tube in a hurry at the tri on Sunday because my rear tire had exploded on the rack ( really more like a loud pop, but still), the woman from High-Tech Bikes who changed my tire inflated the new tube by mouth about a third full before slipping it around the tube, She said it made it easier to handle.

I've not had a lot of luck inflating my presta valve tires, either. I've had the same problem with the poor seal, so I reset the valve and when I pump, the pressure gauge is all over the place, which is why I overinflated the tire Sunday. I saw 130 on the gauge,
but it was obviously a lot higher.

Roxy

**OakLeaf** · 10-20-2009, 04:14 AM

Originally Posted by zia

My valves actually look a little crooked and bent - maybe that's part of the problem.

If the valve core isn't perfectly lined up with the stem after you unscrew it, that's normal. There's no spring in there as there is with Schraeder valves, so it will just sort of rattle around when the valve is open, especially when there's not much air in the tube. That's what makes it hard to start a fresh tube. (Hint on mouth inflation: bite the barrel between your front teeth to hold the valve open. But, mouth inflation to a third full? That woman must have some monster sealing lips... I'm not even going there.

)

If the valve core is crooked when it's screwed down in the closed position, then it should be replaced. (The cores are replaceable, but may be hard to find, so you'll probably wind up replacing the whole tube.)

If the whole stem is bent, then definitely replace the tube.

If the whole stem is coming out of the rim to where it's not parallel with the adjacent spokes, then you need to take the tire off and re-align the tube. Misalignment of the stem stresses the tube where it attaches the valve stem, and can eventually cut the tube.

HTH...

**staceysue** · 10-20-2009, 09:52 PM

Originally Posted by zia

My valves actually look a little crooked and bent - maybe that's part of the problem. It would be good practice for me to change the tubes anyway.

ROFLOL That very thought led me down a path of INTENSE frustration just this morning! Changing tubes is SO MUCH FUN!!!! not

**Lakerider** · 10-21-2009, 02:47 AM

When the bike shop guy showed me how to use the pump, then I did it - it worked perfectly. No hissing, no needle jumping all over the place. It wasn't hard to pump. Now I'm so frustrated that I'm having trouble doing it!!!!!!

I hope to go see him again Friday.

**withm** · 10-21-2009, 06:05 AM

At the Terry website there are some useful videos on this and other subjects. Check out the one explaining Presta valves.

http://www.terrybicycles.com/videos

This is how I do it
Remove dust cap from tube.
Unscrew valve stem. Just the teeny nut at the business end of the stem.

With pump valve closed (parallel to hose) attach pump valve to stem. Be sure to apply it firmly to the stem as far as it will go.

Open pump valve so it is perpendicular to the hose, and in line with the stem.

Pump firmly to desired tire pressure. Speed is not necessary.

Close pump valve (parallel to hose or perpendicular to tire valve stem)

Disengage pump valve from stem by pulling it straight away from stem. This is where I often scrape my knuckles on the spokes. Sigh.

Screw in valve stem nut.

Replace dust cap.

Repeat with other tire.
Go for a ride.

Should just take a minute or two. If you do this before EVERY ride (even if you just did it yesterday) it should dramatically reduce the incidence of flat tires. Well pinch flats anyway. No guarantees against glass or nails.

**Lakerider** · 10-26-2009, 03:30 PM

I took my pump back to the bike shop. The guy there couldn't get it to work right either so he gave me a new one and it works great! If you're having trouble take it back to the shop and have them check it out.

**Lakerider** · 10-20-2009, 02:06 AM

Originally Posted by zia

I have presta valves. I am inflation impaired.

So I set up my floor pump, attach it to the presta valve, flip to the "up" (valve perpendicular to hose tube) position. Lots of hissing. Pump furiously to get more air into the tire than is comes out. Repeat on other wheel.

Argh!

I have a new bike with presta valves and I'm having the same problem. At the bike shop they showed me how to use the pump. I had them to watch me and I did it fine at the shop. Since I brought it home I'm having the same problem you are. I've called the bike shop guy on the phone and talked to him about it. (My bike shop is about an hour's drive away so I can't just run over there any time.) I'm doing everything he's telling me but apparently I'm not doing something right. I plan to go back to the shop in a few days, have them show me again, then have them watch me do it several times until I'm sure I have the feel for it.

Very frustrating!

**Kubla** · 10-20-2009, 04:52 AM

I am so relieved to hear that I am not alone in my struggle to pump tires with Presta valves! There are days (rare indeed) when all goes well on the first attempt, but for the most part I have to allow far too much time for this task.

When it suddenly *does* work, I have no idea what I did that was any different from the multiple frustrating attempts. My biceps are getting quite a workout, though.

**Tuckervill** · 10-20-2009, 06:10 AM

We have a very nice floor pump that I hate to use. HATE it. It holds on to the stem even when it's unlocked that I can hardly pull it off.

So, I dug out the 15 year old foot pump that we bought probably to inflate basketballs, and it works PERFECTLY, even though the lever is all skewed from my husband's gargantuan strength. It doesn't do Presta, unfortunately. Oh the irony.

My Road Morph works great on Presta valves, though.

Karen

**msincredible** · 10-29-2009, 01:35 PM

Originally Posted by Tuckervill

So, I dug out the 15 year old foot pump that we bought probably to inflate basketballs, and it works PERFECTLY, even though the lever is all skewed from my husband's gargantuan strength. It doesn't do Presta, unfortunately. Oh the irony.

You can get an adapter from Schrader to Presta.

**Tuckervill** · 10-29-2009, 05:49 PM

Oh yeah! I have one...didn't need it that day. At least I have one if my dh didn't take it with him and lose it out of his saddle bag instead of leaving it on the valve stem like I do. :-/

Karen

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