Every cyclist in Belfast is aware of the danger of theft. With two bicycles reported stolen in the city every day, you know it is only a matter of time before someone comes for yours and checks the lock.
The police have their systems of entrapment and show videos at conferences of young men wrenching at padlocks, unaware that they are in their sights.
But the assumption of the danger is so engrained that all cyclists now carry locks and chains. You are best having two locks if you are parking your bike in the centre of town.
Yet when city cyclists travel to other towns and into the countryside of Northern Ireland, they find that this investment in security is barely understood.
From Ballycastle to Galway I have seen unlocked bicycles propped outside shops and cafes in a blithe disregard for the thief that would be untenable in Belfast or Dublin.
And it is a pain to have your bicycle nicked. It is your vehicle, for many people the only vehicle they have. The routine of life depends on it.
And often it is a machine you love, not just out of some narcissistic affectation but because you have gone so far and had such fun on it.
Some thieving is opportunistic; some of it is organised. One day recently a group of men pulled up outside the Royal Victoria Hospital and took all the bikes parked there, working along the line with heavy cutters. When a woman stepped forward to rebuke them, one raised the cutters above his head and threatened to fell her.
When a bike of my own was pinched from outside a house in Jerusalem Street I lost all my liberal consideration in an instant.
Because your bike may be worth hundreds or thousands, may be assembled from scrapped parts or may be a sleek and polished racer, but it's yours. It sweetens life and it shouldn't have to be a constant reminder that people walking past you on the street can't be trusted.