Active riding
Weight-reducing action to overcome an obstacle. The trajectory of the center of gravity and the apparent weight discharged to the ground in the different phases are indicated. You can observe that the weight is minimal at the obstacle.
In mountain biking, the most common and natural mistake is to stay still and stiff on the bike. It happens even to the most experienced riders when in critical situations fear takes over and the body stiffens. Facing a path without making the right movements while driving, means passively succumbing to the blows of the roughness of the ground, with the risk of getting hurt and damaging the bike. Moreover, some opportunities that the path can offer are lost.
The active guide consists precisely in making the right movements that derive from actions of "momentum". With momentum, it is possible to soften the impact against an obstacle, or skip it completely (bunny hop), increase the grip of the wheels on the ground in corners, and also gain speed in flat sections without pedaling (pump the bumps).
The most basic action that can be taken is what we called the 'weight-reducing action', but let us begin by saying what our objective is.
When we are riding a bumpy path and hit an obstacle with the wheels, we feel an impact that disturbs the driving. Our intention must therefore be to soften the extent of the impact as much as possible, and this can be done by assessing the parameters that determine it. There are many, such as the feed speed, the wheel radius, the height of the obstacle, and the weight discharged to the ground by the bike-rider system.
To understand how each of these parameters affects the extent of the impact I recommend you to read the book "The science of Mountain Bike riding: the physics behind MTB skills". For the time being, we will analyze exclusively the effect of weight.
The active guide consists precisely in making the right movements that derive from actions of "momentum". With momentum, it is possible to soften the impact against an obstacle, or skip it completely (bunny hop), increase the grip of the wheels on the ground in corners, and also gain speed in flat sections without pedaling (pump the bumps).
The most basic action that can be taken is what we called the 'weight-reducing action', but let us begin by saying what our objective is.
When we are riding a bumpy path and hit an obstacle with the wheels, we feel an impact that disturbs the driving. Our intention must therefore be to soften the extent of the impact as much as possible, and this can be done by assessing the parameters that determine it. There are many, such as the feed speed, the wheel radius, the height of the obstacle, and the weight discharged to the ground by the bike-rider system.
To understand how each of these parameters affects the extent of the impact I recommend you to read the book "The science of Mountain Bike riding: the physics behind MTB skills". For the time being, we will analyze exclusively the effect of weight.
The higher the overall weight, the greater the impact. Also, the load on the front wheel affects the tipping risk.
The best thing would be to jump the obstacle, to avoid it completely, but this is not always possible. Therefore only one possibility remains, minimizing the load on the wheels through momentum, which allows you to "fake" your weight. Performing the same actions as in an even jump, without however reaching the point of detachment from the ground, always maintaining contact with the pedals, a weight-reducing action is exerted. If there was a large scale under the bike, we would see that the overall weight of the bike-rider system would reach a minimum value the moment after the push phase. The mass and therefore the real weight has not changed, it is the dynamics of the motion that makes them seem smaller, the so-called "apparent weight".
It is similar to what happens when we go down in the elevator and feel lighter because our apparent weight has momentarily decreased.
Therefore, we just have to make this gesture at the appropriate time, that of the impact against the obstacle: approach the obstacle in the basic position; just before the impact create a high momentum so that at the moment of impact the apparent weight of the bike-rider system is minimal; maintain a speed that allows both wheels to pass in the reduced weight condition.
For any information, to suggest a topic or to simply have your say, find the contacts you can write to.
The best thing would be to jump the obstacle, to avoid it completely, but this is not always possible. Therefore only one possibility remains, minimizing the load on the wheels through momentum, which allows you to "fake" your weight. Performing the same actions as in an even jump, without however reaching the point of detachment from the ground, always maintaining contact with the pedals, a weight-reducing action is exerted. If there was a large scale under the bike, we would see that the overall weight of the bike-rider system would reach a minimum value the moment after the push phase. The mass and therefore the real weight has not changed, it is the dynamics of the motion that makes them seem smaller, the so-called "apparent weight".
It is similar to what happens when we go down in the elevator and feel lighter because our apparent weight has momentarily decreased.
Therefore, we just have to make this gesture at the appropriate time, that of the impact against the obstacle: approach the obstacle in the basic position; just before the impact create a high momentum so that at the moment of impact the apparent weight of the bike-rider system is minimal; maintain a speed that allows both wheels to pass in the reduced weight condition.
- What care must be taken not to make active driving dangerous ?
- What are the dynamics of the bunny hop and in what direction do we have to push to jump higher ?
- Why does pumping a bump make us gain speed ?
- Why can shock absorbers, if the right actions are not taken, hinder our active guidance ?
- ...
For any information, to suggest a topic or to simply have your say, find the contacts you can write to.