Bicycle Tyre Valve Research
09/06/2014
It's just a simple thing you would think.
All I want to do is pump up my bike tyres.
All I want to do is pump up my bike tyres.
My bike, an old New Zealand brand Healing 10-speed, has two different wheels. (It's a long story)
The front one is steel, the type it originally came with; this has the type of tyre valve I have seen on bikes since I was a child.
The rear one is aluminium, has a slightly different diameter, and has a car-type tyre valve favoured these days.
The front one is steel, the type it originally came with; this has the type of tyre valve I have seen on bikes since I was a child.
The rear one is aluminium, has a slightly different diameter, and has a car-type tyre valve favoured these days.
The problem is matching the two different valve types
to both the hand pump I take with the bike, and the pump for cars at garages.
to both the hand pump I take with the bike, and the pump for cars at garages.
Q. Which exact type is on my bike back wheel?
Types of car valve
Schrader
- American and most common on nearly all cars worldwide
- Larger, 8mm diameter. Has spring to close valve
- External thread Metric: 7.7 mm OD, thread root diameter is 6.9 mm × 0.794 mm pitch.
- Internal thread Metric: 5.30 mm OD × 0.706 mm pitch. (takes the threaded valve core)
A. Schrader
The Shrader type is OK at the garage pump, because the chuck is press-on. An internal part of the Schrader valve presses on a release valve inside the chuck, allowing the air to flow out of the chuck. The chuck's air pressure then opens the tube's Schrader valve, and the tyre begins to inflate. Once the desired pressure is reached, the chuck can be removed quickly and the Schrader closes without allowing air out of the tyre.
However, with the screw-on hand pump connector, the Schrader valve remains open while you are unscrewing the connector, and a lot of pressure is lost. It is annoying to get good pressure with lots of pumping, only to have it leak away while unscrewing the connector.
However, with the screw-on hand pump connector, the Schrader valve remains open while you are unscrewing the connector, and a lot of pressure is lost. It is annoying to get good pressure with lots of pumping, only to have it leak away while unscrewing the connector.
Q. Which type is on my bike front wheel?
Types of bike valve
There are three used on bicycles. (One is the Schrader car type above, and the other two follow.)
(Go the whole hog here: - Indian Standard)
Presta
A valve commonly found in high pressure road style and some mountain bicycle inner tubes (Wikipedia). It is smaller than the below. 6mm diameter, no spring, held closed by internal pressure (also called Sclaverand valve or French valve).
Dunlop/Woods
Mentioned all over the web, but I cannot Google specs in text form. Definitely mine.
A. Dunlop/Woods valve.
Types of bike valve
There are three used on bicycles. (One is the Schrader car type above, and the other two follow.)
(Go the whole hog here: - Indian Standard)
Presta
A valve commonly found in high pressure road style and some mountain bicycle inner tubes (Wikipedia). It is smaller than the below. 6mm diameter, no spring, held closed by internal pressure (also called Sclaverand valve or French valve).
Dunlop/Woods
Mentioned all over the web, but I cannot Google specs in text form. Definitely mine.
A. Dunlop/Woods valve.
Q. How to adapt the garage Schrader chuck to my Woods valve so I can inflate both tyres at the garage?
Looking more promising is this 38th hit, listed as:
"Valve adaptor with rubber O-ring. Use this on a Presta (or the older English/Woods valve) to enable pumping from a service station pump."
The bike shop sold me a Woods valve adaptor to the Schrader size that looks like it. However, it doesn't work with the garage Schrader chuck as there is nothing inside the adapter to open the internal valve of the chuck. You press the chuck to the valve and nothing happens.
I cannot find a diagram for the chuck on the internet. You can get them from China for US$ 0.50 each, but who knows what is inside?
Some chucks (few these days) have a pressure-applying lever at the chuck, these will work.
Update: -
I discovered the Woods adaptor I have is probably not meant for the garage chuck.
It works fine to connect my hand pump's rubber connector with a Schrader fitting to the Woods valve. This is because the pump connector does not have a valve, the air just flows to the tube when you push on the pump.
Now I can leave the adaptor on the bike's Woods valve and I don't have to carry both Woods and Schrader rubber connectors for the pump.
A. No solution found.
"Valve adaptor with rubber O-ring. Use this on a Presta (or the older English/Woods valve) to enable pumping from a service station pump."
The bike shop sold me a Woods valve adaptor to the Schrader size that looks like it. However, it doesn't work with the garage Schrader chuck as there is nothing inside the adapter to open the internal valve of the chuck. You press the chuck to the valve and nothing happens.
I cannot find a diagram for the chuck on the internet. You can get them from China for US$ 0.50 each, but who knows what is inside?
Some chucks (few these days) have a pressure-applying lever at the chuck, these will work.
Update: -
I discovered the Woods adaptor I have is probably not meant for the garage chuck.
It works fine to connect my hand pump's rubber connector with a Schrader fitting to the Woods valve. This is because the pump connector does not have a valve, the air just flows to the tube when you push on the pump.
Now I can leave the adaptor on the bike's Woods valve and I don't have to carry both Woods and Schrader rubber connectors for the pump.
A. No solution found.
Q. How to get around the loss of pressure when disconnecting the hand pump from the Schrader valve?
I have searched "schrader with hand pump disconnecting".
Update 12/2023: - I am afraid "link rot" has killed all three links below.
This product seems to be aware of the problem, especially Question 5 at the bottom.
This product addresses the problem rather expensively at US$49.00, but is called a Shock Pump; I'm guessing it is designed
for low-volume high-pressure work on bike shock-absorbers (Dampers, actually :-)
This site acknowledges the problem but gives no solution.
A. No solution found.
I have searched "schrader with hand pump disconnecting".
Update 12/2023: - I am afraid "link rot" has killed all three links below.
This product seems to be aware of the problem, especially Question 5 at the bottom.
This product addresses the problem rather expensively at US$49.00, but is called a Shock Pump; I'm guessing it is designed
for low-volume high-pressure work on bike shock-absorbers (Dampers, actually :-)
This site acknowledges the problem but gives no solution.
A. No solution found.
So far then: -
I can pump the Woods up by hand, but not at the garage, except maybe sometimes.
I can pump the Schrader up at the garage, but not satisfactorily by hand.
I can pump the Woods up by hand, but not at the garage, except maybe sometimes.
I can pump the Schrader up at the garage, but not satisfactorily by hand.