Wow, I just love technology, it brings us things like that where previously it would only have been witnessed by one.......and try getting anyone down the pub to believe that it actually happened.....great find
That clip was all over the news here a couple of months ago - it happened on a local mountain bike race.
To answer Bing's question, the antelope - a Red Hartebeest (Alcelaphus caama) - did not go for the biker, it was merely trying to get away.
They are great to hunt for meat, in case anybody was wondering...