All I want to do is pump up my bike tyres.
My bike, an old Healing 10-speed, has two different wheels. (It's a long story) The front one has the type of valve I have seen on bikes since I was a child. The rear one has a car-type tyre valve favoured these days.
Q. Which exact type is on my bike back wheel?
Types of car valve: -
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)
This one is OK at the garage pump, because the chuck is press-on, once the desired pressure is reached, it can be removed quickly without allowing air out of the tyre.
With the screw-on hand pump connector, the 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: -
Go the whole hog here Indian Standard
One of three used on bicycles. (Other two are above and below.)
(also called Sclaverand valve or French valve) is a valve commonly found in high pressure road style and some mountain bicycle inner tubes (Wikipedia)
Smaller, 6mm diameter, no spring, held closed by internal pressure.
Mentioned all over the web, but I cannot Google specs in text form. Definitely mine.
A. Dunlop/Woods valve.
The bike shop sold me a Woods valve adaptor to the Schrader size.
It doesn't work with the garage Schrader chuck, there is nothing inside 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 (few these days) chucks have a pressure-applying lever at the chuck, these will work.
Update: I discovered the Woods adaptor is probably not meant for the garage chuck.
It works fine as an adaptor to connect my bike pump's rubber connector with a Schrader fitting, to the Woods valve. Now I don't have to carry both Woods and Schrader rubber connectors for the pump.
Q, How to adapt the Schrader chuck to my Woods valve so I can inflate it at the garage?
and the top hit is EXACTLY the opposite of what I want :-)
"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."
I can almost guarantee it will not work at the service station pump. As I said above, there is nothing inside to open the internal valve of the chuck. It will work with a hand pump because the pump connector does not have a valve.
A. No solution found.
Q. How to get round the loss of pressure disconnecting from the Schrader valve?
Search "schrader with hand pump disconnecting"
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.