Why are Skulls Linked to Riders?

We often see riders with skull tattooed on their arms, back and thighs. Not only that, patches, sculptures, pins, banners, designs and other stuffs connected to riders are somewhat invaded by this gruesome design. What is its significance and why are they used by riders? It is a well-settled principle that the things used by a person reflects his character. Isn't it morbid to use skulls or 'death heads' to identify you? It may mean terror, death, evil and graveyard. It may put a person tobad light and prejudice, isn't it? It is hard to reckon why skulls have become an acceptable design in the 21st century. Moreover said acceptance has continued up to the present time. Others may treat it as demonic, frightening, dangerous and doomed icon. On the other hand, there are those who are taking it as cool and attractive artwork. LuckyMojo.com has given an explanation to this. Catherine said, "Bikes and low-riders, as well as some members of the military , utilize the skull as a significator of reckless machismo barely protected from disaster or doomed bravery that accepts its fate". Why are skulls en vogue? First because it is a symbol of bravery and greatness. If you use it then you will likely to be perceived as brave or the opposite of coward or frail. Therefore the skull's influence can redound to the image of the person using it. Though, the use of this designs and icons can be treated as a 'defense mechanism' still, a lot of people are using it to give an air of confidence and satisfaction for themselves. Machismo is something that lifts men's ego. Thus, this machismo thing keep them on the track to do dangerous and risky activities like going into wars, riding and racing. It's the thing the keeps them going!