Countersteering a Bike
The strange riding fact: to start a left turn, a moving bicycle first steers a little right. That wrong-way twitch moves the tire contact patch out from under the rider, creating the lean that becomes the turn. Canvas 2D · bicycle dynamics.
1 · Straight is balanced
Rolling straight, the wheels stay under the rider. With no lean, the bike has no reason to carve.
2 · To turn left, steer right first
The front wheel makes a short wrong-way move. The support point shifts right while the rider's mass keeps moving, so the bike begins to lean left.
3 · The lean becomes the turn
Once the bike leans left, the front wheel steers into the lean and the path curves left. Countersteering is the little trick that creates the lean.
4 · Mirror it to the right
A right turn starts with the opposite twitch: steer left, lean right, then carve right.
5 · Too small and nothing happens
A weak pulse barely creates lean. A rider adds a tiny handlebar impulse until the bike tips into the arc.
6 · Your turn
Use the controls. More speed or trail makes the steer-lean feedback crisper; zero trail makes the model sluggish and harder to settle.