1. 3D riding on gravity assisted terrain - Be heavy or be light at any given point (alternate these two states all the time). Don't be ALWAYS heavy or ALWAYS light. Be like a wave: heavy-light-heavy.... (as per Brian Lopez's book) Here is a video example. Pay attention to pedals loading-offloading (especially at 2:45 onwards, but really throughout the entire video)
- Heavy- press into the pedals on easy smooth terrain
- Light- offload your weight (from the handlebar and pedals) on difficult terrain (offloading is done either "collapsing" DOWN (elbows and knees moving down) or moving UP by pulling and by taking the weight off the suspension
- 3D means that you move up and down (loading offloading) in addition to the 2D plane
3. On steep downhill terrain balance on your PEDALS! This will tell how much back you should move. Heavy feet, light hands. Here it is very important unless you want to be a superman!
4. On downhill terrain move back as you go over the obstacle and as the bike dictates it at that particular moment. Don't set yourself back in advance. Otherwise you are a human catapult ready to shoot over the handlebars! (it is a bad thing, by the way)
5. Descend leading with your CHIN (this helps look ahead and keep the right ready/attack position). The chin should be low.