Tubeless tyres that won’t stay inflated

Any tips for tyres that just won’t stay up?

Put a new tyre on my road bike, needed to put a tube in to seat it initially, but got it sealed. Did the Stan’s dance a few times, left in in different positions and have done a couple of ~3hr rides without needing to top it up. But left for >24hrs it deflated and unseats, and then I gave to get the compressor out again.

I think if it was kept inflated it would probably seal up, but is there anything else I can do?

Check where is it leaking from by submerging it in water or spraying soapy water on it.

Could be lifted or damaged rim tape or valve stem not sealing properly.

store it in a vacuum?

maybe try to identify where the air is escaping from? is it a valve? the bead? the sidewall? the spokes? then you can work out how best to approach it

It’s nearly always the tape

It’s nearly always the tape

For me, it’s always the valve.

Spraying it with soapy water will often help identify the leak, though it’s mostly a tape issue. Is the tape applied across the full width of the rim? If so then you’re either looking at a bead/tape leak, which should show a bubble at the approximate location, or a tape/tape leak whereby the air is escaping at the overlap point.

“Valve” leaks are often caused by a poor seal between the valve and the tape. Tidying up the tape at this point can help, though the sealant usually does a good enough job.

Of course, you could also have a puncture, or porous sidewalls.

store it in a vacuum?

I actually thought that’s what I need, but sadly I don’t have access to a large vacuum chamber ? I realise this probably wasn’t a serious suggestion BTW.

The problem is the leak is big enough for it to lose enough pressure to unseat, but small enough that I can’t detect it. I reseated and inflated it two hours ago – it’s still reading the same pressure or near enough, and spraying soapy water around the rim, spokes and valve hasn’t yielded any indication.

Side note: I’ve found loose valves to be a problem in the past. I 3D printed this little tool to help, so this one’s nice and snug. https://www.printables.com/model/38268-presta-valve-nut-loosening-tool

A vacuum chamber would only make things worse, a pressure chamber is what you need 🙂

Where’s the bike stored? Might not be applicable but I had one that took the longest time to diagnose. I thought someone was playing silly beggers as the rear tyre would be flat at odd times when I got to the bike to go home from work – turned out that where I left the bike the the sun hit the rear wheel in the afternoon, enough to warm the tyre, soften the tape and the extra pressure to cause a burp where the tape wasn’t quite 100% adhered on one section!

A vacuum chamber would only make things worse, a pressure chamber is what you need

I see your thinking, but a vacuum would pull the tyre outwards and keep it on the rim… all a bit hypothetical though! 🙂

Where’s the bike stored?

I’m impressed you managed to work that one out! Mine is hanging in dark windowless part of the garage though.

I used to have the same problem with my tubeless tyres until a friend introduced me to a remarkable solution – it was like a circular rubber inflatable sausage type thing.

I now put them in all my tyres & you can even take a spare with you in case one breaks.

Put on another layer of tape?

I used to have the same problem with my tubeless tyres until a friend introduced me to a remarkable solution – it was like a circular rubber inflatable sausage type thing.

That was the solution I resorted to with this wheel last time I tried to convert this wheel to tubeless. It works, but it’s suboptimal for all the reasons that are debated in a million other places on the internet.

Put on another layer of tape?

This was how I got it to this point. It hasn’t noticeably lost pressure overnight. Maybe this thread has changed it into staying up. Otherwise, a third later might be the answer.