blow into/thru a Dunlop valve

[Emanuel Berg]

If you blow into a Dunlop valve, from either
direction, and then compare this to doing the
same thing with another Dunlop valve, the
amount of air that gets thru isn't the same.
But what is the difference, exactly?

--
underground experts united
http://user.it.uu.se/~embe8573

[AMuzi]

On 4/23/2018 6:36 PM, Emanuel Berg wrote:
> If you blow into a Dunlop valve, from either
> direction, and then compare this to doing the
> same thing with another Dunlop valve, the
> amount of air that gets thru isn't the same.
> But what is the difference, exactly?
>

Air going in passes through the top pin hole under the
rubber tube segment and into your inner tube. Air cannot go
back out the other direction through that hole so one must
undo teh top nut to let air escape ( as you noted in prior
post).

I think what you describe is one valve which works and one
which is damaged. Usually just replace the rubber tube
segment. Those were once included in patch kits but are now
less commonly found.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[Emanuel Berg]

AMuzi wrote:

> Air going in passes through the top pin hole
> under the rubber tube segment and into your
> inner tube. Air cannot go back out the other
> direction through that hole so one must undo

> teh top nut to let air escape (as you noted
> in prior post).

Right, then the preassure from inside the tube
dislocates the whole thing, away from the
opening to let the air out?

But just isolating the valve, how does it (the
valve) work? The rubber is a loose lid over
a cylinder. Blow from within the little pipe,
the lid lifts just a bit to let thru air.
Blow from the outside, it stays down?

(Here the "outside" is actually the inside of
the tube.)

Is this correct?

Why does the Dunlop deteriorate? The rubber
looses its freshness/moisture to shrink and not
cover the hole? What about lubing it?