that I can keep in my camelbak for adapting a petrol station air line to fit a Presta valve? If I’m out and I get a puncture I tend to be able to get enough air into the fixed tube to get me home or back to the car (gently), but nowhere near enough for hard/rugged riding. If I could stop at a service station and top up the air to a rideable pressure I could keep riding. . . .

cheers

Yes. I have them fitted to my Presta tubes, to extend the valve a bit, as the rims are quite deep section.

Yep, I keep on in my camelbak. IIRC I got it from halfords.

1. you need a new pump
2. yes they exist – loads on ebay for a couple of quid
3. if you cut the top of a standard dust cap it does the same job

Get a decent pump? But yes they are available. Its just a bit of brass with an internal thread in presta size and an external thread in Schrader size.
Google is your friend. (google presta valve adaptor schrader)

IME they are not always terribly reliable tho – due to the lengths of the threads being different on different tubes.

Here

you’ll be looking for one of these. your lbs is likely to have them. if not, then pretty sure halfords stock them.

however, if you’re going to return to your car after puncture than why not just take a track pump with you?

best of all – get a decent pump for out on the trails / nip down the gym and work up your arms a little. 😉

Ebay link for valves!

Just bought 10 nice ones from ebay

I have em on all my bikes and in each camelbak.

Excellent – I’ll get myself one. I tend to carry a mini pump with me – which I can use to get enough air into the tube to get me back home or to the car. I do usually have a track pump in the car, so if I get back to the car I can top up the tube and go out again. Problem is I’m sometimes 15 miles from the car but only 5 miles from the nearest petrol station.

cheers