Unicycling on Big Bang

My son called me in to the living room whilst I was making breakfast with this shout “Mum, unicycle’s on the tele”.

It was a short piece on one of the British sky programmes (possibly on discovery). It was about how bicycle wheels are gyroscopes without the cage, but that you don’t even need 2 wheels. (or something like that).

Gaz Top says “How do you unicycle?” after failing miserably to ride without moving (didn’t anyone tell him that he had to pedal?). Anyway, unicycling guy says 'You need 3 things - practice, balance and more practice".

Anyone know who it was?