Now there's a thought, squirt it through the valve hole and you could have invented the first self inflating tyre :-)

Yeh, I wondered about that.

I thought water vapour pressure might be an uncontrollable variable, but people who understand the gas equations tell me this is unlikely to be a real-world issue.

The CO2 pressure with such a setup is, however, likely to be difficult to control without an adjustable pressure release valve on your tyre, but that doesn't sound as complicated as a tyre pressure monitoring system, whiich I'm told many cars do have nowadays.

Not any of mine, obviously, but still...

MIGHT generate corrosion and/or mold long term, which latter could be a health hazard for tyre fitters.

Havn't thought of any other snags so far....Oh dear, ANOTHER patent opportunity gone.

I'll NEVER get my luxury yacht at this rate, though I do have some ideas for making a cheap one...

Now there's a thought, squirt it through the valve hole and you could have invented the first self inflating tyre :-)

Self inflation should reduce internal oxygen exposure rather more efficiently than filling with nitrogen.

The oxygen will still diffuse through the tyre wall, but it'll be continuously removed by the scavenging of the yeasts residual oxidative metabolism..