A woman rides a custom bike during "Bike Kill 12" in the Brooklyn borough of New York City, October 31, 2015. "Bike Kill" is an annual gathering of builders and riders of home-made bicycles that culminates in a tall bike jousting competition. (Photo by Stephanie Keith/Reuters)

These snaps show a pair of daredevil bikers performing gravity-defying stunts as they get covered from head to toe in brightly colored powder. The stunning action shots show the fearless duo perform nail-biting tricks on their BMX bikes as they get showered with the brilliantly colored powder. The amazing images were taken by Christoph Jorda, from Bavaria, Germany, with bikers Thomas Kaiser and Konstantin Ottner. Here: The biker with the holi powder behind whilst performing stunts. (Photo by Christoph Jorda/Caters News)

In this April, 2015, photo provided by DC Shoes, daredevil Robbie Maddison in his latest stunt rides his motorcycle across waves in Tahiti, French Polynesia, using ski-like devices on his wheels. (Photo by Tim McKenna/DC Shoes via AP Photo)

Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

One of the highlights on the Audi stand is the bicycle technology concept known as the Audi e-bike Wörthersee – a sport bike that does not fit into any of the usual categories. It is neither a pedelec nor a conventional bike, but is best described as a high-end pedelec made by Audi for sport, fun and tricks. The Audi e-bike Wörthersee combines the Audi brand’s principal competences – design, ultra, connect and e-tron – and explores the limits of what is technically feasible in terms of design, lightweight construction, networking and electric mobility.

An mechanic in Brick Lane Bikes repairs a fixed wheel bike in their shop in Shoreditch on June 14, 2011 in London, England. The UK bike industry has seen a dramatic rise in the number of people building their own custom bikes or purchasing bespoke bikes. (Photo by Oli Scarff/Getty Images)

People ride bicycles in Halloween costumes during “Bike Kill 13” in the Brooklyn borough of New York City, October 29, 2016. “Bike Kill” is an annual gathering of builders and riders of home-made bicycles that culminates in a tall bike jousting competition. (Photo by Stephanie Keith/Reuters)