Precipitous mountain roads, specially-modified bikes, and deadly consequences. Simon Maybin spends time with the young men who race down the steep roads of Colombia\u2019s second city Medellin. Marlon is 16 and he\u2019s a gravitoso - a gravity biker. He hooks onto the back of lorries or buses climbing the precipitous roads to reach high points around the city. Then, he lets gravity do its thing and - without any safety gear - hurtles back down the roads, trying to dodge the traffic. This year, two of his friends have died gravity biking and Marlon has had a near-fatal accident. But he\u2019s not quitting. So what drives young men like him to take their lives into their own hands? And what\u2019s being done to stop more deaths? <\/p>
Presenter\/producer: Simon Maybin <\/p>
(Image: Marlon with his bike ready to ride back down into Medell\u00edn. Credit: Simon Maybin\/BBC)<\/p>\n