The cyclist uses steering impulses and body weight displacements to control the lean his bicycle. This lean (i.e., the deviation from the vertical position) is important both when driving straight ahead and when taking a turn:
- When riding straight ahead, the lean must remain small, otherwise people will swing too much from left to right.
- When cornering, the correct lean angle must be chosen, appropriate to the bicycle’s speed and the sharpness of the turn.
A cyclist can control the lean of his bicycle in two ways:
- By giving steering impulses.
- By moving his body weight from left to right and vice versa.
We already discussed the role of steering impulses when cornering on the page about countersteering. The role of steering impulses in riding straight-ahead is based on the same physical principle, but the rider’s goal is different. Specifically, if the bicycle leans to the left (right), the rider can correct this by applying a pressure on the handlebars in the same direction: by applying a pressure to the left (right), the bicycle leans to the other side. By dosing the pressure on the handlebars, the bicycle can be set exactly upright. It is not always necessary that the front wheel is visibly turned; what matters is that pressure is put on the handlebars in the same direction as the lean.
Besides the handlebars, the cyclist can also use his own body weight to keep his bicycle upright. Specifically, by leaning his upper body to the left (right), the cyclist also displaces his center of gravity to the left (right). This displacement causes the bicycle to lean in the same direction. However, this way of leaning the bicycle is much slower than by pressing on the handlebars. If you want to quickly put your bicycle upright, you have to quickly and accurately press on your handlebars in the direction of the lean.