still see the odd bit of 20" cyclo trials on sky
my brother used to work for a guy who made them, and i had a go on one. this was almost 10 years ago. the bikes was featherweight and the brakes were hydraulic (very good)
hopping about was easy. from standing still it was easy to hop 180 and land on the back wheel. then hop 180 off the back and land on the front etc.