Stupid Pump/Presta Valve Question

bakerstreet

Evening all.

I bought a Giant Mini Pump 2 for my recently purchased Defy 2.

Thought I would pump up the tyres before commute tomorrow morning and I'm a bit confused about how the pump locks onto the valve.

I'm used to the old fashioned car style valve where you just screw the adapter on and away you go.

I've undone the dust cap and I squeeze the pump onto the end and it can't seem to lock onto anything.

There is what looks to be a green bung in the centre of the pump, but I don't want to wrench it out of the pump if its an important part...

I would look at the manual, but the bike shop fitted the pump whilst servicing the bike and with that they chucked out of the packaging...

Any help would be greatly appreciated

nicklouse

one of these?

http://www.giant-bicycles.com/en-gb/par ... 380/30936/

desweller

On Presta valves there is also a small nut that locks the valve pin down as well as the plastic dust cap, you'll have to unscrew it so the valve can pop off its seat when you're pumping it up.

chocothon

2 things:

If it looks like the one posted above, then you push it onto the valve and then pull out the handle on the back of the pump head to lock it on.

but before that...

These pumps are made to fit both Presta and Schrader and have a small washer inside the pump head which has a different hole size on each side of it (thats the green bung you can see). The nut on the pump head comes undone (make sure you are somewhere where the bits won't drop and get lost). Then you can reverse the washer inside depending on what your valve is, so that the hole is the right size to fit the valve.

antfly

You really need a decent track pump, I suggest a topeak with a smarthead. And don't forget to unscrew the valve.

bakerstreet

Thanks for all the replies

Its a Control Mini 2 Plus.

Its not designed to be a main pump, its something to have on the bike for emergencies. I'm hoping santa will bring me a proper pump

I can see that there is something to undo when you take the dust cap off., do I just unscrew it until it won't unscrew any more?

So I have to unscrew the mains circular nut at the top iof the pump and reverse a washer then the pump should clamp on?

Couldn't cycle in this mrnoing as I had stuff that I needed to bring in for work. Will have a go tonight

chocothon

This should be handy off youtube:
http://www.youtube.com/watch?v=Ehf6HL0aLTc

bakerstreet wrote:

I can see that there is something to undo when you take the dust cap off., do I just unscrew it until it won't unscrew any more?

-- Yes, do it gently though its quite a thin thread - as long as you unscrew it to somewhere near the end of the thread it will be OK.

Then try the pump again. By the sound of it you've got a Presta valve inner tube (Schrader are larger diameter without the small threaded insert). So if you look into the end of the pump nozzle, the aperture should look about the same size as the inner tube valve. If it looks more like a car valve sized aperture, then you'll need to swap the pump washer around.

Then, if you need to:

bakerstreet wrote:

So I have to unscrew the mains circular nut at the top iof the pump and reverse a washer then the pump should clamp on?

-- Yes, if you undo the knarled nut on the pump, the first thing you'll see is a softish insert. It has a smaller internal diameter on one side than the other and you can take it out, turn it around and reinsert. So, as you've got the smaller Presta valve on your bike, you need the smaller aperture facing outwards from the pump.[url][/url]