Presta Valve - Help!

[colinr]

So I tried to put some more air in my tyre, never used a presta before. Looked up instructions on the internet and did this:

• Removed valve cap
• Unscrewed the top bit leaving a few mm of visible thread on the long threaded bit.
• Attached pump, started pumping.
• Hisss..... tyre defaltes completely in seconds, can't get any air in it at all now.

Have I done something extremely stupid? Is there anything I could possibly be doing wrong that means it's not inflating? Pump definitely works, tried another one that definitely works just in case.

 

[summerdays]

Is it one of those pumps where you can use it on both different types of valves... are you certain you have put them together correctly.

I know I had the same problem as you when I first changed to presta valve but I can't remember what I did/didn't do.

 

[adscrim]

Check the tube at the rim hole. If you've pulled to hard on the valve, rough edges on the rim hole can 'slice' it open!

 

[betty swollocks]

You have to jam the pump on hard.
Have you got the pump nozzle set to presta?

 

[colinr]

It was set on presta... I've torn the valve where it joined the inner tube. So that's what happens when you tighten it too much then?

 

[Big John]

A valuable lesson learned, eh? You must have muscles like Popeye

 

[colinr]

I just thought it seemed a bit loose! Didn't want to interfere too much. It looks like it's torn rather than cut on a sharp hole - too much waggling while pumping with a handpump? I tried to steady the valve as I pumped as it said. Nice walk home ahoy!

 

[betty swollocks]

You need to jam the pump on hard and keep the nozzle still on the valve while pumping.
Take the pump off with a sharp knock downwards on the pump when the valve at the top. DO NOT wiggle the pump nozzle off!

 

[adscrim]

use the tube to make protective 'washers' for your other tubes! a holepunch sized hole normally works quite well. Don't leave too much excess rubber around the hole though.

 

[colinr]

Old inner tubes are useful for everything! I'm sure I didn't wiggle the pump on/off, must've been in-pump-wiggling. Now I don't have the right spanners to get the wheel off... what's what about planning ahead?

 

[gbb]

I just thought it seemed a bit loose! Didn't want to interfere too much. It looks like it's torn rather than cut on a sharp hole - too much waggling while pumping with a handpump? I tried to steady the valve as I pumped as it said. Nice walk home ahoy!

One point colin (or anyone else using these pumps), depending on your pump type.
Certainly, the Zefal pumps have a 'nut' over the rubber seal you put onto your valve. I always undo that nut a bit when i put the pump on the valve. This allows the rubber seal to expand somewhat. Its easier to get the pump onto the valve.
Once on the valve, tighten the nut and inflate. This ensures a tight fit on the valve.
Once inflated, undo the nut a bit..again, it allows the seal to expand, allowing you to get the pump off easier, without straining everything.

Does that make sense ?

 

[colinr]

Does that make sense ?

Err... I have this:

Do you mean the bit at the top-right of that pic, or is this a different type of pump?

I think investing in a track pump is next on my shopping list. The P word is bad enough, don't need self-inflicted flat tyres too!

 

[gbb]

This 'nut' colin..i think you're on the right track...

But dont do what i did....forget to tighten the nut up when you've done. Lost it somewhere mid-ride. Did'nt realise till i really needed it

 

[Randochap]

I'm sure I didn't wiggle the pump on/off, must've been in-pump-wiggling.

Get a Topeak Road Morph.

 

[fossyant]

That's not a nut - it's a dust cover. That blackburn is fine - I've had one for some time.

One - ditch the metal nut on the presta valve which you use to tighten onto rim - that induces stress when pumping.

With the blackburn, you just pop it on the valve, and flick the lever out to lock on.

You just need to put less stress on the valve, that's how you've damaged the join.