This is really just the opposite of way steep descending (DUH!). You need to find the balance point as you climb, which moves forwards on the bike the steeper you go.

On a fairly steep climb leaning your body forward (Road bike aero style) puts enough of your weight forward on the bike to do the trick. On the steeper pitches you have to resort to moving forward on the saddle. If you think about descending for a moment, you end up stretched out, as you move back, whilst still holding on to the bar (well most of us keep holding on to the bar) When climbing you do the opposite and end up scrunched up towards the bar. This feels (and looks) a bit strange, but when the trail is really steep maintaining this position (and keeping pedaling) are the keys to going up. Most people say 'hover just above the nose of the saddle'. Well this is true, but if you have a WTB saddle (or any with a long nose) it is possible to sit on the saddle nose and keep pedaling. This really works but can be hugely uncomfortable so hovering it is.  Use a very low gear (DUH again) and spin the pedals furiously whilst  keeping your body still. This requires enormous energy from such a cramped position.

The leaned forward climbing positionThere is a way of getting even more power and traction from your rear wheel however. When climbing in the weight forward (crunched up) position, there's a limit to how much power you can apply to the pedals without the tyre slipping. On a long steep climb, smooth pedalling from the balance position is essential to prevent wheel spin, which occurs on the down push (the most powerful part of the pedalling stroke). For very short steep pitches pulling up hard on the bars with  your hands, to counteract the force of pushing on the pedal, can be incredibly effective. What happens is that if you pull up with your left hand whilst pushing down with your  left leg, the rear wheel is momentarily forced down in to the ground. If your efforts are synchronised the wheel won't spin out even with your strongest powered pushes. This kind of power is essential if you want to climb the 'impossible' steep pitch on your favourite rides.

The technique needs to be practised (although some people get it right first try) and is not dissimilar to the roadie 'honking' from a forward position. Remember to use left hand to pull up when pushing with  left leg, and right hand to pull up when pushing with right leg. Don't forget to lean forward, move your weight forward and pedal at a quick rhythm, but don't hit the slope too hard or you may  lose balance.

The Hill Start

Starting  on a steep climb can be very difficult. The key point is to jump  straight in to the crunched forward climbing position. Straddle the bike and clip in with your favourite foot just a little forward from  the top of the stroke (this is the position where most power can be  applied). Hop very quickly on to the saddle (in the forward position)  and power down immediately. Don't worry about clipping in with the  other foot at first, just pedal with your foot resting on the  unclipped pedal until you're underway.

Other essential climbing tips: