How countersteering works

To turn a bicycle you first steer a little the other way. That brief outward steer is what makes the bike lean in. It is called countersteering.

What it is

Countersteering means briefly steering the front wheel away from the direction you want to turn. To go right, the bars turn a little to the left. The bike then leans to the right, and once it leans you let the bars turn to the right to hold the turn.¹ A common way riders put it is “press the inside grip”: to turn right, press the right grip forward. That follows from the geometry (pushing the right grip forward turns the wheel to the left); it is a riding rule of thumb rather than a quotation from the sources.

Why it works

A bicycle only turns steadily when it leans, and the combined centre of mass of bike and rider must lean first.¹ Steering the wheel to the left moves the front tyre contact point out to the left of the bike. Seen from the turning bike, a centrifugal torque then leans bike and rider to the right, into the turn.¹ The same geometry is why a steer toward an unwanted lean moves the contact points back under the rider, which is how you balance.²

The spinning wheels also add a roll moment in the same direction, but it is small: in Fajans’ model about 3 % of the centrifugal one for a motorcycle, and less for a bicycle.¹ That is a model result, not a figure for every bike. In 1970 David Jones cancelled the gyroscopic steering torque of a bicycle with a counter-rotating disk and could still, barely, ride it no-hands.³ Later work showed that a bicycle can be self-stable without gyroscopic or caster effects.³

What the rider feels

The bars resist for an instant and then the bike drops toward the inside of the turn. Once it is leaning, the steer angle is in the direction of the turn, and how much torque the bars need depends on speed and bike geometry.¹ Most cyclists countersteer without noticing, and the initial wrong-way deviation can be only a few centimetres.¹ It is one way to start a lean; hip thrusts and other movements work too.¹

Where the lean angle comes from

The countersteer sets the lean; speed and corner radius decide how much lean the turn needs. In a steady turn the lean angle of the combined centre of mass is θ = atan(v² / (g · r)), with speed v, gravity g and radius r. This is the standard simple model; it is not worked through in the sources below. A rider who leans their body differently from the bike gets a different frame angle, and Krengo measures the frame. At 30 km/h and 15 m that is about 25.3°, the same worked example as in the glossary; try your own numbers in the calculator. That is the model value, not a measurement of any ride.

Sources

1. J. Fajans (2000), “Steering in bicycles and motorcycles”, American Journal of Physics 68(7), 654–659. doi:10.1119/1.19504
2. J. P. Meijaard, J. M. Papadopoulos, A. Ruina, A. L. Schwab (2007), “Linearized dynamics equations for the balance and steer of a bicycle”, Proceedings of the Royal Society A 463, 1955–1982. doi:10.1098/rspa.2007.1857 (Whipple and Carvallo showed in theory that a bicycle can balance itself.)
3. J. D. G. Kooijman, J. P. Meijaard, J. M. Papadopoulos, A. Ruina, A. L. Schwab (2011), “A bicycle can be self-stable without gyroscopic or caster effects”, Science 332, 339–342, which also describes D. E. H. Jones’ 1970 experiment. doi:10.1126/science.1201959

The three papers were read in full or in part on 5 October 2026; Jones (1970) is cited through them, not read directly.