That rider in the pic is Ron Commo III, hes the #5 Pro Rider in the US. Very talented. In that pic he is riding a 125.
Trials technique for logs...
1st read this..
The double blip technique is used for obstacles which are shorter in height then
the wheelbase of the motorcycle and often slightly angled. In the double blip
technique the rider approaches the obstacle at slow to moderate speed and blips
the throttle to lift the front wheel. The rider bends his knees to allow the
motorcycle to come up to him while staying centered. If done correctly the front
wheel strikes a glancing blow off the obstacle and changes direction to parallel
up the surface of the obstacle. At this point the throttle is reduced to allow the
rear suspension to uncompress. The rear suspension should be fully uncompressed
when the rear wheel reaches the base of the obstacle. Just before the rear wheel
contacts the obstacle the throttle is again blipped to drive the rear wheel into
the obstacle. As this is happening the rider straightens his legs to help drive
the rear wheel into the obstacle as well as get his weight over the front wheel.
The throttle is snapped off to allow the rear wheel to drive up the face of the
obstacle while at the same time the rear suspension begins to uncompress. The
rider again bends his knees allowing the rear of the bike to come up under him.
The unloading rear suspension pivots the bike forward around the axis of the
swingarm and the drag of the decelerating motor pivot the motorcycle around the
rear axle. The reason there is a limit to the size of the obstacle for this
technique is that the front wheel cannot be in tight contact with the obstacle
when the rear suspension unloads for the second time as both front and rear will
just push you backwards off the wall. The most common error in the double blip
technique is not shutting the throttle off between blips. This causes the rear
suspension to stay loaded which doesn't allow the motorcycle to efficiently change
the direction of force from straight forward to up. If done properly the rear of
the motorcycle does not hit the base of the obstacle with any more force then is
necessary to grab traction for the climb.
Then watch this
These should help...a lot.