|Four cross (4X) mountain biking|
|Around the Academy:
Four cross or 4X mountain biking can get very hairy indeed!
Four riders compete on a specially designed highly-challenging course.
The races last between 25 seconds and one minute and are usually fast and frenzied.
The courses are a mix of natural and man-made obstacles covering a steep descent.
The dizzying array of obstacles include stutter bumps, doubles, table tops, step ups, drop offs, moguls, bermed or off-camber corners and gap jumps.
The difficulty of getting over these obstacles at high-speed whilst being jostled by three other competitors means there are plenty of crashes.
The knock-out rounds can be decided by a series of heats called 'Motos' with riders competing three times before moving on to quarters, semis and final.
The final consists of the last four riders left in the competition.
Alternatively, riders compete against the clock to decide seeding positions before moving into the knock-out stages.
All-rounder Steve Peat, former BMX champ Dale Holmes, brothers Daniel and Gee Atherton and Scott Beaumont are Britain's best four crossers.
In the women's event, Tracy Moseley and Fionn Griffiths, better known as downhillers, fly the flag.