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Questions tagged [valves]

Valves allow air to enter pressurized chambers (such as tires and suspension forks) and remain there. Common bicycle valves include Presta, Schrader, and Woods valves.

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valve stem caps on tubeless tires

On my road bicycle with tubed tires ridden only on paved roads, I never used the caps that covered the tube stems. Now that I have switched to road tubeless tires, do I need to use the caps to reduce ...
pisapete's user avatar
3 votes
1 answer
237 views

When I press down on my presta valve cap when it is open why is no air coming out

I recently got my bike and it rides great. When I went to pump up the tubeless tires I realized that the presta valve cap isn’t letting air out when I press down on it when it is open. I looked on ...
Super Random Local Facts's user avatar
9 votes
4 answers
1k views

Repeated punctures at the base of the valve stem

I get many punctures at the valve stem in my 29 inch mountain bicycle. any tips to avoid them? The hole with leaking air is marked with green circle (click for larger): The rim with rim tape next to ...
yigal's user avatar
  • 289
4 votes
3 answers
1k views

How does a Presta valve core work?

I would like to understand how Presta valve cores work. A Presta valve core contains all of three screws: the top nut screw (brass part, right side of the image), the valve cap screw (with notches ...
Sam7919's user avatar
  • 9,268
2 votes
2 answers
466 views

How do I stop a removable valve core from leaking?

This Presta valve core, here removed, has been a nuisance since day one. Once inflated, it holds the pressure well for a trip to the trails, but after 3-4 days, the wheel is flat again. The volume (29&...
Sam7919's user avatar
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0 votes
1 answer
77 views

Leaking valve hole

I tried different valves with no luck and used gorilla tape for inner wheel so I don’t think it’s the valves and I’ve taped it making sure. I’ve covered all the holes. I am at my wits end with ...
Derek  McLaughlin 's user avatar
0 votes
0 answers
91 views

New presta valve core leaks

I have tubeless tires with sealant and there was sealant leaking from both presta valves after using a broken bike pump on them. After it it seems like the sealant clogged the valve a little bit and ...
Jerry's user avatar
  • 1
2 votes
3 answers
521 views

Dunlop valve with schrader chuck compatibility

I have a dunlop (or woods) valve that I would like to inflate. I am trying to avoid needing to screw on a chuck, so I was looking at some options online to be able to do this, but most chucks that ...
BarrelOfNapkins's user avatar
6 votes
4 answers
3k views

Valve stem too thick for hole in rim?

The rubber protection cover does not pass through the hole in the rim. Something can be done or not a fit? This valve has a rubber reinforcement that does not pass through the hole in my rim. The hole ...
nightrider's user avatar
  • 7,879
1 vote
1 answer
167 views

What DT Swiss Valve and Tubeless Tape fit DT Swiss Wheels 2291335 and 2569868?

I recently bought the Endurace CF SL 7 eTAP bike and it came with DT Swiss wheels. DT Swiss front wheel 2291335 DT Swiss rear wheel 2569868 What DT Swiss valve would I use for my front and rear wheels?...
Killesk's user avatar
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4 votes
1 answer
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repeated punctures at the valve stem

I just had a puncture at the valve stem on my front wheel. 29 inch mountain bike replaced the inner tube had to leave the bicycle outside at the 90 degrees with direct sun for two hours rode the bike ...
yigal's user avatar
  • 289
11 votes
3 answers
2k views

Why is the retaining nut ("thumbscrew") against the wheel rim for inner tube Schrader valves no longer used?

The Schrader valve retreats back into the inner tube because there is nothing to hold it in place against the wheel rim. Despite having an outer screw thread on the protruding valve nothing is there ...
Roger's user avatar
  • 111
5 votes
2 answers
3k views

How to prevent a Presta valve core from unscrewing when disconnecting a pump [duplicate]

My mini-pump has a screw-on head (as I guess most of them do) and several times when removing the pump from the valve, it's taken the valve core out with it. The last time this happened to me on the ...
Will Vousden's user avatar
  • 3,991
2 votes
1 answer
607 views

Dunlop valve core comes off with the cap

Could someone please enlighten me if my valve is broken? I think this is a Dunlop valve but the core seems completely stuck to the cap. No matter how much I twist and turn the core always comes off ...
Wiktoria's user avatar
6 votes
2 answers
258 views

Why are thorn resistant tubes prone to valve stem failures?

I would welcome knowledgeable answers rather than opinions please. I have been cycling 50+ years and now work in an LBS. I have seen numerous examples of so-called “thorn-proof” TP tubes, of different ...
Henry S's user avatar
  • 267
2 votes
3 answers
432 views

How to carry heavy loads tire safe?

I have been buying 12 kilograms of bottle packs once a week and it seems like the valve on back wheel can't handle it. I have been getting valve failures and last time I noticed air leaking but it ...
user2617804's user avatar
3 votes
1 answer
143 views

Should I replace this tube or try to replace the core?

I just borrowed this old bike and realized could not pump up the back wheel. When I saw the valve, it looks like the valve core is missing. I tried to install a new presta core but it did not fit. ...
Teewip's user avatar
  • 33
2 votes
1 answer
2k views

Leaking Dunlop valve when I inflate my tire

I just bought a new bike for my daily commute. When I try to inflate the rear tire using a Xiaomi air compressor, I noticed air escaping at the junction of the compressor and valve, making impossible ...
Kano's user avatar
  • 23
-3 votes
1 answer
303 views

Why are presta valves better than schrader valves [duplicate]

I have a couple of bikes and tire sizes. Some have presta valves some have schrader valves. I find the the tires that have presta valves hard to pump and that they seem to lose air way more often. ...
mo_maat's user avatar
  • 175
7 votes
5 answers
2k views

Considering modern bicycle trends (2021), why are presta valves still the dominant design?

The usual trope justifying the use of Presta valves over Schrader valves is no longer logical (in my opinion at least) because of changes in wheel, rim, and tire systems. Let me exemplify by refuting ...
MaplePanda's user avatar
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4 votes
4 answers
1k views

"Soft" valve insert for easier pumping

I've just bought my first bike in 20 years - a 29" mountain bike. And, inevitably, I've just got my first puncture in 20 years, and a lot has changed. The first thing I noticed is that today's ...
Phirun's user avatar
  • 41
6 votes
2 answers
1k views

What are these female connectors called?

I need help finding out what these female connectors/attachments are called so that I can buy them for my air tank project. Basically these are found on those portable air compressors which connect to ...
Kokachi's user avatar
  • 163
3 votes
2 answers
4k views

How does a Schrader valve work

So I have a new bicycle which has a Schrader valve on it. So I was wondering how does a Schrader valve actually work , the anatomy of it etc. The best I was able to find was something like this: But ...
Kripke Platek's user avatar
-2 votes
2 answers
1k views

Gary fisher Marlin serial # WTU087C2290C

What’s the age of the bike? Can I use either a schraeder valve or presta valve tube for the wheels?
Suheil's user avatar
  • 1
-1 votes
2 answers
127 views

Is this a Schrader valve?

Is it possible to determine from these 2 photos, whether this valve is a Schrader valve (i.e. the type of valve that is also found on automobile tyres) ?
rowote's user avatar
  • 1
5 votes
2 answers
3k views

broken presta valve confusion

Not a big bike person so my information could be wrong. My bike tire leaks air whenever I fill it and I know its coming out of the valve hole. I did some research and found that its a presta valve so ...
Pete's user avatar
  • 51
4 votes
2 answers
968 views

Presta to Schrader valve adapters that don't screw on the valve core

Do any exist? I want to easily use a gas station compressor without worrying about popping my valve core out when I unscrew the adapter after use. No, I don't want to "just use Schrader-valve ...
Gregory Leo's user avatar
  • 1,305
7 votes
3 answers
2k views

Unable to pump air in my bicycle tube

I am a new biker. I got some tubes to replace, but I am not able to identify the valve, I try to force air with presta convertor but the moment I remove it air blows off in a second. Please help ...
padma's user avatar
  • 163
5 votes
3 answers
5k views

Why did my valve pin bend? Is there anything that I can do to help it without any specialized tools?

I have a new bike (been less than a month since it was purchased) and has been ridden for about 600km (375 miles) on bad city roads. What may have caused this bend of the valve pin? Is it possible ...
Timon's user avatar
  • 386
-1 votes
1 answer
3k views

Standard or specification for diameter of valve stem holes

I have a rim with a Presta valve hole, but I would like to drill it out to fit a Schrader valve. Is there a specification for how large the hole should be? I want to be sure the hole isn't too big, ...
BetterSense's user avatar
  • 3,446
3 votes
2 answers
222 views

Bits "peeling off" schrader valve?

I've got a bike that hadn't been used in a while until a couple weeks ago, it was in a place where it gets direct sunlight (I'm trying to fix that) and as a result some things like the seat have ...
Gregorio Litenstein's user avatar
1 vote
1 answer
385 views

How do I inflate this bicycle tire valve? [duplicate]

I inherited this bike with this funny looking stem. Is this broken? How do I inflate it?
David's user avatar
  • 111
4 votes
2 answers
2k views

What is the typical structure and location of a check valve in a floor pump?

I decided to take apart a Bontrager reCharger floor pump recently on a whim, one of those whims during which you pay no attention at all to what you're doing. After putting it back together, the pump ...
plodsmeade's user avatar
2 votes
2 answers
3k views

How to fix this unusual looking valve stem to put air in the tire?

I'm wondering how do I fix this valve stem? I want to put air in the tire. But, i don't see the usual screw-on stem part. The other bicycle tire has such type of stem, so I am thinking this one is ...
Matthew Kooshad's user avatar
3 votes
1 answer
4k views

Tubeless valve leaking, what exactly is wrong & what do I need to do to fix it?

My front tyre has started to leak air at the top of the presta valve. It's very noticeable when the valve is unscrewed or even not really tightly screwed in: you can feel a breeze coming out of the ...
Scottmeup's user avatar
  • 1,427
2 votes
1 answer
353 views

What is this valve and how do I fill it?

This is the valve in one of the tubes on my bike: What kind of valve is this, and how do I fill it? I originally thought it was a Presta valve, but it doesn't look or work like any of the presta ...
GrixM's user avatar
  • 137
1 vote
2 answers
136 views

Can anyone help identify this valve?

Can anyone help identify this type of valve? (see picture below). I've recently bought this bike and am having trouble inflating the front tyre correctly. Any help is greatly appreciated. Cheers
Joel Schiffler's user avatar
5 votes
1 answer
353 views

What does the number 77 mean on the Schrader valve?

Can anyone please tell me what this number on the valve mean?
Lisa's user avatar
  • 51
5 votes
1 answer
2k views

Can I repair this valve stem hole?

Today I got a stick wedged between my frame and tubeless valve stem. In addition to snapping the stem I widened the hole a bit. Any suggestions on how to fix it? Current plan is to go over the whole ...
dranxo's user avatar
  • 198
0 votes
1 answer
342 views

Tube valve cap keeps breaking

For some reason, my valve caps keep breaking. I'm not sure if it happens while I ride or while my bike is not in use, but often when I take the caps off to fill the tubes before riding, I find one of ...
Jay Schauer's user avatar
15 votes
5 answers
6k views

Are there valve caps that show the tire pressure?

I saw these valve caps for cars, set at 2.4 bar: Is there something similar for bicyles? it would help less careful riders when it's time to pump more air in them.
FarO's user avatar
  • 307
10 votes
3 answers
4k views

What air attachment screws onto a Presta valve with the core removed? High volume for seating bead?

I have presta valves on two of my bikes. I have a presta floor pump. I have an air compressor. I have a schrader adapter. I have a blowgun and a tire inflator for my compressor. I can attach the ...
Aubrey Robertson's user avatar
8 votes
2 answers
5k views

How does this hand pump work

Some time ago I bought this pump. It should be usable for all valves, but I'm not sure how that is supposed to work and it didn't come with a manual. On one side there's a lever, on the other side (...
Berend's user avatar
  • 818
2 votes
2 answers
15k views

Can't get bike valve caps off

I will sound a bit thick but i'm no bike mechanic, to give you an idea of what make my bike is here are some pics (the bike isn't mine and the owner doesn't know). the problem is that I cannot get ...
Laponski's user avatar
3 votes
2 answers
658 views

Diameter of valve hole in the inner wall of the rim

Let's say I have presta valve, so the outer hole in the rim is 6 mm (the visible hole). However rim can have inner "wall" inside with inner hole in it -- to my surprise the hole has bigger diameter. ...
greenoldman's user avatar
  • 2,064
2 votes
2 answers
3k views

Inner tube valve cut from stretched rim tape?

I was trying to fix my sisters flat tire to make some money by charging her fees cheaper than the bike shop. I found the leak to be on the actual valve piece. Near the base there is a small cut ...
Broke Biker's user avatar
1 vote
2 answers
2k views

Is there a pump / Schrader valve adapter that prevent leakage during disconnection?

My tyres are rated at 120psi and I like to inflate them close to that. My pump is electric with presure indicator. If I just unscrew the pump and connect it back the pressure drops by about 20psi. I ...
Aelian's user avatar
  • 205
1 vote
2 answers
7k views

Presta or shrader valve for mtb?

Is it better to use presta or shrader valve for tubeless conversion on a mtbike, 29" 2.20 tire, and why?
Alex Par's user avatar
  • 579
1 vote
3 answers
370 views

Valve extender snapped off

Yesterday I crashed, and somehow the front wheel landed on a rock or something that made my valve extender break. The bottom part of it is still stuck in the valve it extended. It's a tubular tire so ...
oftedal's user avatar
  • 111
4 votes
7 answers
681 views

How can I avoid tearing the valve loose from an inner tube with a wheel lock?

The problem It sounds foolish, but I have too often torn the valve loose from the inner tube by rotating the wheel so that the valve is pressed against a closed wheel lock. Wheel locks are common in ...
PJTraill's user avatar
  • 221