I don't think we are in complete control of everything happening in our lives but often, the unlucky luck is the product of something we did or didn't do. Let's say your bike. It could be that something happened to the brakes while you were riding - like going through some oil which made the tires so slippery that the brakes couldn't grip. But more likely, the brakes weren't checked for a long time. the pads got brittle, the cable got weak, something like that. they could have been replaced....
I think you get where I am going. Lots of "luck" and "bad luck" is a result of prior actions.

visiting you from thealliance :)