What features make a BMX special?
Top BMX rider Bethany Shriever has just taken part in the World Championships in Colombia, South America.
The 17-year-old won a silver medal in the junior women's time trial on Saturday and won all her races to reach the final last eight.
But a mistimed move on the opening jump saw Bethany crash out of the final.
So what is so different about BMX rather than regular cycling?
Bethany has taken time out to talk us through her BMX's special features.