epic gives good advice about arms being bent when descending.
however, the notion of getting "behind the saddle" really is something that you must learn by doing. the steeper the descent, the farther back you must get. this is an example of body position for a descent of about 20-30 degrees slope (after doing a vertical 4-foot drop): http://www.imagestation.com/picture/...2/fdc7720e.jpg
-- notice how I'm pretty far back and my arms are almost straight. this is because I can steer by minor tweaks of the handlebar and skidding the rear wheel in a given direction. skidding is not recommended UNLESS the terrain is already loose and disturbed. NEVER skid on virgin terrain or a trail that is in good condition.
important reminder: two reasons for getting back, (1) unweight front wheel to prevent stabbing into a stopper rock - which would cause an endo; (2) more weight over rear wheel, which adds braking power to rear. in the above picture, I was using both reasons to get my butt back.
in a descent you don't want to be using much front brake UNLESS traction is EXCELLENT and then, only gingerly.
anticipation is a result of knowing your bike and the terrain. you can aid anticipation by looking as far ahead as the trail will allow. the last thing you want to be doing is looking too close to your front wheel. this prevents you from "setting up" for corners, climbs and descents. you end up reacting to an emergency, rather than planning and choosing your line/strategy for a particular trail feature.
on a trail that's new to you, you should look ahead and trust your body to use its reflexes to make the bike do what you ought. this is something that takes a conscious effort. when I am riding "skinnies" (elevated features that are 12" wide or narrower), I am more inclined to look right in front of my front wheel. this is BAD. so, I always tell myself "two bike lengths ahead!" and then rely on my instincts and skills to keep the bike following the skinny. it's amazing how well your body knows what to do merely from a remembered visual input.
feel free to ask any questions that this might prompt. [img]smile.gif[/img][ July 08, 2002, 08:17 PM: Message edited by: gonzostrike ]