Bleeding air while using track pump

[Jon George]

Okay, what am I doing wrong? I'm ensuring the Presta valve has been partially opened (and experimented with it fully open), done a test bleed to ensure it's not sticking, and believe I'm locking the track pump head off correctly. (Mine seems to be one which locks tight when the lever is in same plane as valve and loose when at right-angles.) And yet I'm always racing to get more air in than that which bleeds out. New Pump needed? New technique? New hobby?

 

[Peteaud]

Air does not leak out of a presta, even with the end undone.

 

[snorri]

Pumps are funny things, after you get used to them you wonder why you ever had a problem.

 

[Cubist]

Sounds like you need a bit more practice. Are you sure the head of the pump is properly set up for Presta for a start? If it's a dual headed pump you need the narrower, deeper of the two openings. If it's a swappable head you need to make sure the rubber insert is the right way round, and if it's one of the Bontrager dual purpose ones it'll be OK from the off.

Next, unscrew the valve lock all the way. The locking mechanism in the pump head may be squeezing on the knurled thingy rather than sealing properly.

 

[robgul]

... or you may be pushing the pump head too far on to the valve which pushes the sprung seal in so that it doesn't do what it's supposed to do - or conversely the pump head isn't far enough on the valve.

An alternative is to get a Presta/Schraeder converter (a small brass ferrule, Halfords sell them) - it screws on the Presta valve (with the seal unscrewed) and then as the name implies a pump with a Schraeder head is used (the connection is a bit more forgiving)

Rob

 

[Andrew_Culture]

If it's an Aldi special it will leak like a government department after a pay-freeze.

If it's a Joe Blow or similar it shouldn't leak.

 

[Jon George]

Air does not leak out of a presta, even with the end undone.

This provided a clue as to what is probably happening ...

... or you may be pushing the pump head too far on to the valve which pushes the sprung seal in so that it doesn't do what it's supposed to do

And this confirms an experiment I made last night after watching several YouTube clips with no discernible sound and thinking I CAN do that!.

Thanks folks - a little bit more practice and I might just have a totally silent experience myself.

 

[ayceejay]

You are going to need a few stronger swear words than that in my experience.

 

[Jon George]

Solution has arrived in the shape of a Joe Blow Sprots 2. Previous pump bought from LBS, but then,nothing lasts forever. (New mantra for 2014: The best is cheapest in the long run.)

 

[Andrew_Culture]

Solution has arrived in the shape of a Joe Blow Sprots 2. Previous pump bought from LBS, but then,nothing lasts forever. (New mantra for 2014: The best is cheapest in the long run.)

Is it yellow? I think that's the one I have and it's one of the best bits of kit I ever bought. I also have a cheap track pump from Aldi which is as useful for inflating tyres as boiled celery.

 

[Jon George]

Is it yellow?

That's the bad boy. I'm impressed.

 

[alecstilleyedye]

my new bike came with the cheapo inner tubes, and do leak when using the track pump, whereas the various vittoria, continental and ritchey tubes in the other bikes don't at all.

i'm expecting the lifeline tubes bought from wiggle to leak through the valve under inflation too…

 

[Leaway2]

Is it yellow? I think that's the one I have and it's one of the best bits of kit I ever bought. I also have a cheap track pump from Aldi which is as useful for inflating tyres as boiled celery.

Same experience here. The Aldi may be OK for lower pressures. My Joe Blow is the dogs dodahs.