We are connected to our bike with our hands and feet. Although we sit on the saddle and can move our hips to aid in control of the bike, we often have to rise out of the saddle into the Ready Position to prepare for more challenging terrain. When in the Ready Position, our arms and legs act as our suspension. We may brag about the couple inches of travel that the bike suspension provides. We can get 6 or more inches of free suspension from our arms and legs.
When traveling in our vehicles, the wheels move up and down with the imperfections in the road surface as we sit comfortably behind the wheel. Similarly, we want our torso to remain relaxed while riding our bike. The bike will be moving around beneath us on the terrain. The difference in motion between the bike and body is called Bike / Body Separation.
Bike / Body separation is a fundamental skill in allowing us to navigate challenging terrain such as climbs, descents, high speed corners, and rock, root, or log obstacles. The relationship between bike and body can change in three dimensions; forward and back, side to side, and up and down.
We move our body weight forward or back to remain in balance over undulating terrain, climbs, and descents. As we roll up a climb, we have to shift our body weight forward to keep the front wheel form rising off the ground. Conversely, we shift our body weight back when on a descent to avoid tipping over the handlebars.
|Forward position while climbing.|
|Lean back while descending.|
|Forward on the front slope of an undulation or "whoop".|
Side to side Bike / Body Separation is primarily used to control your path or direction. When cornering at high speed, we lean the bike in the direction we want to turn. The more we lean or separate from the bike, the faster we can go. Conversely, when we want/need the wheels to track through a specific path, we lean from side to side with our body to maintain balance over the tires.
|Basic side to side motion.|
|Leaning the body to keep the bike on a specific path.|
|Leaning the bike during a high-speed corner.|
The last dimension of Bike / Body Separation is up and down. We often apply up and down forces on the bike to control our traction. Compress your body and weight down during a corner to increase traction. Extend up or lift body weight to lighten the bike over obstacles. We will talk about this later when we discuss Pressure Control. An extreme example of up and down Bike / Body Separation can be seen when performing a "Bunny Hop" or when you lift the bike off the ground. This is extremely useful to clear obstacles while maintaining speed.
|The phases of a "Bunny Hop".|
In the photo above, the rider compressed down as you would do to a spring. Then explodes upward. As he passes over the object, he pulls the bike up closely under him. Then extends down and lands. Upon landing, he again compresses to soften the landing and maintain control.
There you have it. Bike / Body Separation is absolutely critical to most of what we do on our bikes. Mountain bikes using these principles will feel a special bond between the bike and the flow of the trails. Even cyclocross and even roadies can benefit from a solid understanding of these movements.
Thanks for reading.