What’s the max pressure you’ve ever used in these things?

I only go as high as 60psi in mine and it works fine for my 26*2.25 tyres. I do put an old curtain over it, just in case.

What’s your highest pressure?

Coke is capable of getting to at least 6bar, haven’t needed to go above 4.5bar. I’m more worried about over pressurising the tyre than bursting the coke bottle tbh.

The plastic pipe on mine starts leaking faster than I can pump above around 50psi, so I stop then. That’s always been plenty.

It’s the volume as much as the pressure.

iirc 60psi used to be the ‘coke factory bottling’ pressure.
I’ve seen them blow at 130psi – in water rockets – and pieces cut a cotton shirt. 🙁

130/1.5 then I guess-that’s about 85psi (6bar). No need to go that high anyway.

I only ever need to go to 4 bar.

I tested mine to 150psi. With water, and duct tape on the bottle. And earplugs and a roll of carpet on top. So yeah it’ll do it but as others have said, you don’t need it.

Air volume and flow rate are more important. Short tubing. Large bottle 3L.