BMX world champion Mariana Pajon to test London track

World champion Mariana Pajon will compete on the Olympic BMX track for the first time at the 2012 test event 19-20 August.

The 19-year-old who hails from Medellin, Colombia's second-largest city, has already won 14 global titles.

Great Britain's three-time world champion Shanaze Reade is one of her idols.

Read more: Reade set for key BMX test event

You can watch a special Olympic Countdown programme on BBC Two on Sunday at 1300 BST.