"Soft" valve insert for easier pumping

Question

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 bikes all now use the car-type valve. When I tried pumping the tyres with an "el cheapo" football pump, no way could I get air into it. Had to buy a car-type pump.

Now that I've bought a valve insert removal tool, the reason is obvious. The spring that closes the valve is so strong that pump pressure cannot open it: it's necessary to use the clamp-on adaptor that seizes the valve thread and pulls a pin into the valve to hold it open against the spring.

If memory serves, the old push-bike valves used a simple rubber sleeve over the insert that acted as a one-way valve when pump pressure was applied.

Are these still available, or are there "softer" valve inserts available that make pumping tyres easier for kids to do without having to understand the reason for the clamp-on adaptor?

Answer 1

With the car (Schrader) valve it also happens to me that I cannot start pumping. Usually when there is still some pressure in the tube. I am only creating a very high pressure region between the valve and the pump head. That means the pin is not pressed correctly. What normally helps is to remove the pump head and seat it again and better.

Pumping a Schrader valve in a good condition should not really require immense forces, no matter if you have a track pump in your workshop or if you ise a portable mini-pump. You should be able to achieve reasonable pressures in both conditions.

Note that the ruber sleeve valve (or its modern version with a plastic ball) still exists and is popular in the Netherlands and Germany and often called the "velo" valve - in other regions it is known as the Dunlop valve. The reasons for a larger popularity of some valve over the other types in certain regions are mostly historical and random, not really some objective technical superiority.

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Advice:

You can certainly buy Dunlop/Velo inner tubes from a different country, if they cannot be sourced locally. Buy whole tubes, not just inner cores to put into your existing valves.

I strongly suggest, however, to go to a bike shop with your wheel first and let them test a different pump for you. You may find out that with a proper pump (no matter if small or big, jist with the right pump head) it will be easy to pump what you already have.

Answer 2

Cyclists today know the automotive style to which you refer as the Schrader valve.

The valve with a rubber sleeve that you mention is called a Dunlop valve, also known as Woods. Within Dunlop valves there are two types: the older kind you're referring to that use a rubber sleeve and no spring, and a version that's now taken over in many places that uses a spring in a conceptually similar manner to a Schrader valve. My rough understanding for that change is the sleeve design was more subject to failure due to the rubber of the sleeve degrading, but I have no basis for an opinion on the veracity of that because my handling of any of them is limited to a handful of bikes I've serviced that were brought over to North America. I think I replaced some faulty old-type Dunlops with Schraders on a Japanese shopping bike once.

If newly manufactured sleeve-type Dunlop valves are available, they're a rarity as far as I know, and likely something you would need to check in with an antique/restoration type specialist business about, although I wouldn't be surprised if a working mechanic in a Dunlop valve country had a better answer than that. (Edit: laolux points out in the comments that sleeve type Dunlop is still common in Japan.)

The bigger picture question of effort required to inflate a tire deals more with the size of the pump's air chamber and the target pressure on the tire, and the amount of air being moved per input force.

Answer 3

Whenever you have to open a spring (or the Dunlop rubber hose) with every pump stroke, you loose pressure. I.e., pumping is harder and the max pressure you can achieve is more limited. The old-fashioned rubber hose is less tedious than the Schrader valve spring, but since you mention kids: when I was a kid, I found pumping against the rubber hose very tedious, so we changed the Dunlop inner valves for alligator (aka flash) ones which are ball valves.

There are several possibilities to achieve easy pumping.

• Dunlop ball valves. If you test them with your mouth, you can easily blow them open with your lungs (not even cheeks) which means a small fraction of a bar.
  (Though they sometimes need one initial hard stroke if the ball got stuck to the closing position after a longish time there)

• There are also Dunlop inserts with springs that are much weaker than the Schrader springs or the Dunlop rubber hoses, they are OK as well.

• For Schrader valves, you can use either a pump that presses down the pin, so you don't have to open the spring by air pressure,

• but there are also adapters that make a Schrader valve compatible with a Dunlop/Scaverand size pump. The better ones consist basically of a pin to open the Schrader spring and a ball valve, mine cost < 5 € IIRC.

• (Sclaverand valves also have weak springs and are thus easy to pump)

Also, are the more dead volume you have (hose between pump and valve) and the smaller the volume of the pump cylinder (mini pump), the more of the pump stroke is wasted in compressing air into that dead volume.

Answer 4

To summarize, there are three main types of valve used for bicycles: the Dunlop, the Schrader and the Presta. All three are incompatible, and it's best to buy a tube with a fitting for the desired valve. However, adapters are available for those willing to experiment. I've ordered some but they've not yet arrived.

A recent entry to the market is the Alligator Express Valve Universal as it's called. The manufacturer's literature provides lots of photos of different housings, valves and adapters, but no clear explanation of how everything fits (or doesn't). The website is one of the worst I've come across:

https://www.alligator-valves.com/us

... listing valves for cars, trucks and motorbikes, but makes no mention of bicycles that I could find. I sent them an email and received:

"Hello, You should be able to acquire from Myers Tire Supply https://www.myerstiresupply.com/ Thank you"

Sure not keen to be helpful. So I've sent a second email to Myers and am awaiting response. At this stage I'll thank everyone for their input, especially cbeleites unhappy with SX who posted the URL of the Alligator brochure which got me onto it, and call it quits.

Every man for himself, and best of luck.