I would not ride that bike, the tyre is defective and not serviceable and is in danger of failure by blowing out. The bird is heavy on the front, unusual to have a bike with a front and rear tyre running the same psi (42) but the Bird does.
That is a failure of the tyre, often due to age as already stated and also as stated, due to things put on it, ie some solvents etc
On a bike the last memory you want to have in life when you negotiate that bend is " that forum thread said I shouldn't ride the bike with the tyre like this"!!!!!!
That's is an immediate pg9 police prohibition and mot failure because pics seem to show it down to construction of the tyre!
Common sense says don't ride it, ,let alone the legal side of it!
Some makes of tyres are better than others and some love some makes, personally if I won a set of Avon tyres I'd be very pissd off in life but some on here would disagree!! Even though I don't like em a set of Avons wouldn't normally do that!
Shit rubber can cause unwanted pregnancy and early departure in life!!