The tube of the bicycle

The tire of the bicycle gradually wears down.
It is danger.
I must change a tire.

I have not changed a tire until 40 years old passed.
Now I experience it several times, I am still incompetent.

When I take off a tire, I take out the air of the tube once.
I air it again after putting on a tire.

A tube may explode, if I do not put on a tire definitely.
I have done it once.

Swelling of the tire was strange.
A tire does not put definitely.
At the moment, it gave a loud sound and exploded.

I am still afraid of airing the tube.
I was surprised like that.

If only I am surprised, there is not the problem.
Then, I have surprised the wife of the neighbor.
I am so sorry.