Presto Valve question
#1
Newbie
Thread Starter
Join Date: Sep 2014
Posts: 3
Likes: 0
Liked 0 Times
in
0 Posts
Presto Valve question
After pumping the tire and removing the pump I found my valve no longer visible, I guess it is jammed inside. How soon should I change it and anticipate that I will get an air leak from that? Is it safe to ride?
Thank you for the advice.
Olga
Thank you for the advice.
Olga
#2
That Huffy Guy
Join Date: Jun 2014
Location: Ashtabula, Ohio
Posts: 1,438
Bikes: Old School Huffy Bikes
Likes: 0
Liked 6 Times
in
6 Posts
Not safe to ride like that. Deflate and start over. Won't deflate because the valve is inside? Buy a new tube and pirce the old one with an ice pick through the hole in the rim. An $8.00 tube now will save from from a long walk home.
#3
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,525
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Liked 3,359 Times
in
1,846 Posts
Broken PV valve stems are about as common as 3 leaf clovers. (maybe not quite that common). It really doesn't natter because a PV is a simple check valve and the tire pressure alone is enough to keep it reliably closed. The only issue is that the OP will now need a pin of some kind to let air out if he wants to.
BTW- the little nut and stem extension aren't somehow jammed inside the valve. They're inside the pump head, or fell out after you removed the pump and dropped on the floor.
Yes, as long as the tire holds air, which it will 99% of the time, the tire is safe. The worst that can happen is that the tire loses air and goes flat, and flats, regrdless of cause are inconvenient, but not dangerous.
BTW- the little nut and stem extension aren't somehow jammed inside the valve. They're inside the pump head, or fell out after you removed the pump and dropped on the floor.
Yes, as long as the tire holds air, which it will 99% of the time, the tire is safe. The worst that can happen is that the tire loses air and goes flat, and flats, regrdless of cause are inconvenient, but not dangerous.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
Last edited by FBinNY; 09-20-14 at 09:13 PM.
#6
#7
It's MY mountain
Join Date: Sep 2006
Location: Mt.Diablo
Posts: 10,017
Bikes: Klein, Merckx, Trek
Liked 3,182 Times
in
1,715 Posts
Even if it holds pressure just fine, you won't be able to add any more air for your next ride. As soon as you blow in some air the check valve will come off inside the tube.
And presta tubes ARE the standard.
And presta tubes ARE the standard.
#8
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,525
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Liked 3,359 Times
in
1,846 Posts
In any case, the OP's valve must still be in place since the tire is holding air. and the WORST case scenario is that she blows it into the tube, and has to replace the tube. Until then it will hold air, so the choice is whether to replace the tube now, to avoid having to replace it alter, or to wait until she has to replace it. As I see it, she has nothing to lose by waiting, and with any luck she can use this tube until it flats for another reason.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#9
It's MY mountain
Join Date: Sep 2006
Location: Mt.Diablo
Posts: 10,017
Bikes: Klein, Merckx, Trek
Liked 3,182 Times
in
1,715 Posts
So the valves in tubulars are somehow different? I never noticed. It happened to me on a clincher on a century - got a flat, changed the tube, turned out my CO2 inflator wouldn't take my cart so some guy lent me his mini pump and I got it pumped up but when I took off the pump there was just nothing there... like a hollow cylinder. When I got to the rest stop I used the mechanic's pump and then the check valve fell out and the tube wouldn't hold air. So maybe it was something more than just breaking off the little nut, maybe my valve in the spare was flawed to begin with.
#10
Yeah. My experience with presta tubes with broken off nuts is they work until I try to add air. Even with the stem at the top pointed down and trying to pump very slowly the poppet get blown irretrievably into the tube. Of course you might get away with it, or perhaps you have a stem that prevents the poppet from going into the tube, but in stems with non-removable cores the stem has clearance to insert the poppet from the inner end during manufacture.
#11
Senior Member
If prestas are the standard, why are they not used on aircraft? Or Busses. or big trucks. or...or...or...
Check to see if your rims can be drilled, change to schraders.
Check to see if your rims can be drilled, change to schraders.
#12
#13
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,525
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Liked 3,359 Times
in
1,846 Posts
1- the stem is narrower, so they allow for narrower rims. Note that this isn't a rim strength or room to drill issue. It's about the sum of widths of the valve and two tire thicknesses which determine the minimum inside width of the rim's tire flanges.
2- they're springless check valves, which makes them ideally suited for hand pumping, and eliminates the need for a valve depressor in the pump head, and/or air loss when the head is removed. This also simplifies the design and use of the pump heads since they need only provide a seal to the shoulder of the valve.
If either reason applies, Presta is a better choice, otherwise it's a toss up.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#14
Senior Member
Yes. They are perfectly suited for deep V carbon wheels. Yay. Most of us are mortals.
And while they are not narrow wheeled vehicles: Tire Pressure On A 747 — Tech Ops Forum | Airliners.net
And while they are not narrow wheeled vehicles: Tire Pressure On A 747 — Tech Ops Forum | Airliners.net
#16
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,525
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Liked 3,359 Times
in
1,846 Posts
IMO this is a natural consequence of placing the need to squeeze every last mil out of the cost vs. producing a product worth putting your name on. Tubulars were relatively expensive and no maker wanted to have his reputation suffer over bad valves. The same used to be true when folks like Michelin, Continental, and others made their own tires and tubes. These days bicycle tubes are completely generic with the source being the lowest bidder, which moves quality to the back burner.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#18
Senior Member
In the world of repairs out in the field, it pays to have the most common items available. OR carry everything you need all the time. At the very least, one of those presta adapters, which get lost easily.
Dear Olga:
You have heard from both camps on this. If you can find a situation that's better than either of these presented, take it.
Sincerely,
Rich
Dear Olga:
You have heard from both camps on this. If you can find a situation that's better than either of these presented, take it.
Sincerely,
Rich
#19
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,525
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Liked 3,359 Times
in
1,846 Posts
BTW- whatever plays out with this tube, if you're going to stay with PV, it pays to learn how not to break the nuts off.
Despite pumping thousands of times (maybe 10s of thousands) since, the last PV valve I snapped the nut off was back in 1968 or so.
It's easy to damage valves, including breaking Shrader valves when hand pumping. It's just as easy not to. The difference is in learning basic techniques for fitting pumps, and properly bracing then when hand pumping.
Despite pumping thousands of times (maybe 10s of thousands) since, the last PV valve I snapped the nut off was back in 1968 or so.
It's easy to damage valves, including breaking Shrader valves when hand pumping. It's just as easy not to. The difference is in learning basic techniques for fitting pumps, and properly bracing then when hand pumping.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#20
Abuse Magnet
Join Date: Jun 2012
Location: Colorado
Posts: 1,872
Bikes: '91 Mtn Tek Vertical, '74 Raleigh Sports, '72 Raleigh Twenty, '84 Univega Gran Turismo, '09 Surly Karate Monkey, '92 Burley Rock-n-Roll, '86 Miyata 310, '76 Raleigh Shopper
Liked 180 Times
in
91 Posts
I don't understand the hate for Presta at all. I've only been using Presta on my bikes for the last few years, but there's no way I'd go back to Schrader. Presta just works better.
#21
Thread
Thread Starter
Forum
Replies
Last Post
mr,grumpy
General Cycling Discussion
5
10-14-17 03:30 PM