Evan van der Spuy was taking part in a race
at Albert Falls Dam in South Africa when the huge buck sprung at him.
The drama is caught on camera by fellow
competitor Travis Walker.
As the Red Hartebeest moves away after the
collision, the stunned 17-year-old cyclist takes several moments to regain his
feet - before showing his smashed helmet at the end of the clip.
He later tweeted: "I'm all stable with
nothing more than a very stiff neck.
"That specialised helmet really saved