Hey guys,
I believe I'm one of the only actual trials riders on this forum.
To understand more about why trials are so completely different than other bikes see my bike in the bike registry:
http://www.twospoke.com/forum/f138/stock-trials-bicycle-5428/
Trials can encompass a broad range of styles but the main goal is to overcome any obstacle, any way possible. Some riders have more of a street bmx influenced style, such as Danny Mackaskill. Other riders have what would be referred to as a "pure" or "competition" style.
Trials competition in the US is rare. However, in europe it is more prevalent. In a competition courses are set up with various obstacles the rider needs to get over. Point are awarded for putting down a foot, hitting a portion of the bicycle other than the tires, etc. The goal of course is to complete with the least amount of points. Riders are NOT allowed to pre-ride the course.
Many bicycle world records are held by trials bicyclists.
For example this is the link to benito ros doing a 1.42 meter sidehop over a bar:
Trials skills can include jumping on the rear wheel from a stop up onto objects or across gaps. (world record gap between two stationary platforms of equal height with NO starting speed is over 13 feet!) Trials riders are now also bunnyhoping to the FRONT wheel first. World class riders can get onto ledges over 5 ft high with no jump to assists.
I'll attach one of my videos here, made a couple years ago: