Weird Puncture

[ASC1951]

I was expecting one of the intellectuals on here to come back with the physics...

Nah. That's why I did Greek, Latin and Ancient History, so that I can pontificate on anything without having to wait for people who might know something about it.

 

[youngoldbloke]

Have one tube on the winter bike with a knurled nut on the valve that is impossible to screw tight - thread on spindle destroyed. Have had no problems with the tyre deflating - as has been pointed out above you need to push the spindle in to release air, so its a bit of a mystery why the OPs went down .....

 

[Ivan Ardon]

That's what I thought too, although I was expecting one of the intellectuals on here to come back with the physics to confirm or rule out this as a likely scenario!!

Some "back of an envelope" calculations. Assuming a 700c wheel and a valve mass of 1 gram gives a speed of a shade over 200 miles an hour before an undone presta valve will allow the tyre to deflate.

 

[Alf]

I have taken to leaving off the knurled nuts. Can't really see what purpose they serve since my tubes don't seem to move relative to the rim once they are inflated. So I don't see how they could contribute to a puncture either.

Alf

 

[e-rider]

I had the same problem and I know what causes it! Was it a schwalbe tube?

 

[youngoldbloke]

I have taken to leaving off the knurled nuts. Can't really see what purpose they serve since my tubes don't seem to move relative to the rim once they are inflated. So I don't see how they could contribute to a puncture either.

Alf

Those knurled nuts are not necessary - though helpful when pushing the pump connector onto the valve when starting to inflate the tube (some valves come un-threaded and without them, after all). The knurled nut I was referring to in my post above was the small brass cylindrical one on the spindle in the centre of the valve assembly that releases the valve when pushed in, and keeps the valve closed when screwed up. (Presta Valves)

 

[raindog]

The knurled nut I was referring to in my post above was the small brass cylindrical one on the spindle in the centre of the valve assembly that releases the valve when pushed in, and keeps the valve closed when screwed up. (Presta Valves)

Yes, this is what I'm talking about too.
Anyway, tyre still nice and hard after several days.
Yours, totally baffled, raindog