Have you check the rim tape for damage or wear?

Have you checked the inside of the tire?

How about the roller on the trainer? Perhaps something sharp on it penetrating the tire.

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Once, I was fast. But I got over it.

New tyre should be here tomorrow so will check rim tape when I install it.. good call!

Nothing on the roller, but as I say I cannot find any puncture on the inner when I take it out just flat? Am I doing something mind bendingly stupid (for once lol)

My go-to is to pump up the tube so it holds its shape (overinflate it essentially) and then put it in a bucket of water section by section, you'll see the bubbles where air is escaping.

Thanks for the response.. did this on the last inner.. no bubbles.

Honestly I am stumped, could I be breaking the valves by manhandling my foot pump or something?

Spray glass cleaner is good for leak finding too

Somebody within earshot is sick of the noise and letting the tyre down...

I have had this happen too. Make sure the valve core is tight. Opening them to inflate the tire can make them loose over time.
Even if it’s not the problem tightening them is really easy and it would rule that out.[/reply]

That is weird. So you took the flat tube which had deflated and inflated it up and put it underwater and no bubbles? Someone else mentioned that you should make sure that the valve core is tight (if it is a removable valve core). Another thing that you could do is put just a small drop of lube on the valve core to make sure that it is seating properly (that there is no resistance keeping it from closing properly). So, really dumb question, but...do you tighten the valve after you inflate the tire (Im assuming a presta)? If you don't, try that.
Stephen J

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I believe my local reality has been violated.
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Happiness = Results / (Expectations)^2

Lol probably my wife

Correct, and yes I am screwing the valve closed...

Honestly this is driving me crazy, changed maybe a hundred flats over the years and never had A problem.

New turbo tyre didn’t Arrive today, fingers crossed for tomorrow and I will do a full clean build and if it happens again the wheel is going in the sea.

Sometimes when the tube has a small enough hole you wont see bubbles unless you have decent pressure in it. The hole does not open much at all if there is not enough pressure difference between inside and ambient. I often have trouble finding the location of leaks on tubes that lose pressure overnight or a little longer so I switched to a soap and water sprayer. Put the inflated tube on the floor of the garage or outside (in the shade so the soap and water don't dry too fast) spray the whole thing down and start searching!

Rich


Edit:
I forgot to add that you can inflate a butyl tube quite a bit with no issues...it will just stretch, sometimes to 2-3 times the relaxed diameter and circumference. But be careful with a latex tube, a little too much pressure and they form a "bubble", a little more pressure and the bubble pops.