How bad can a cut be?

[John the old'un]

Hi Sean,
Close it up with thin superglue.
Always worked for me.
The old 'un.

[BrendanM]

If it's a deep cut you should remove the tyre and make sure that the 'fabric' on the innertube side has not been cut.

At the high pressures used in race tyres it may be possible for the innertube to burst through small holes and create a sudden blowout which could be dangerous.

You could use the tyre on a turbo trainer.