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)

A genetically engineered featherless rooster struts around the campus of the Hebrew University of Jerusalem's Department of Agriculture May 22, 2002 in Rehovot, Israeli. After two years of research, departmental scientists announced the naked chicken, as it has been dubbed, as a low calorie bird because the lack of feathers means the chicken has less fat. It also matures earlier than its feathered counterparts. (Photo by Moshe Milner/GPO/Getty Images)

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)

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)

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.

Participants run at the “Half-Naked Marathon” at Olympic Forest park in Beijing, China, February 28, 2016. This annual running event which requires participants to run half-naked, was organized to promote environmentally friendly lifestyles. (Photo by Kim Kyung-Hoon/Reuters)

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)

This brave swimmer certainly has a brrracing workout each weekend she skinny dips in one of the coldest rivers in Europe which regularly plummets to temperaturess of –9C. Inna Vladimirskaya, 32, strips off on the banks of the Dnieper river, in Kiev, Ukraine, every Sunday morning, and takes a swim after jogging along the snowy banks of the river in the nip. (Photo by David Tesinsky/Caters News Agency)