How many g do you pull in a corner on a bike?
Lean angle and sideways g are the same thing in two units: sideways acceleration in g equals the tangent of the lean angle. At 45° that is 1 g. Most road corners ask for far less.
About the numbers. Every number is a model value from the calculator’s formula (g = 9.81 m/s²). Your line and speed will differ, so read them as a guide. The g values are derived from the lean angle; Krengo shows your lean angle in a corner, and the table below turns it into g.
The rule: sideways g = tan(lean)
In a steady corner the bike leans so that the combined pull of gravity and the corner points along the bike. Geometry then gives one clean relation: sideways acceleration divided by g equals tan(lean). Read the table: 15° is about 0.27 g, 25° about 0.47 g, and 45° is exactly 1.00 g.
From lean to g
The corner’s acceleration is a = v²/r, and a flat circular corner banked at θ needs tan θ = v²/(r·g).1 The lean formula in the calculator, θ = atan(v²/(g·r)), is the same relation. Dividing a by g gives v²/(g·r), which is tan θ, so:
- a = v²/r (sideways acceleration)
- tan θ = v²/(g·r) (lean)
- a/g = tan θ (sideways g)
Most corners ask for little
The table gives both sideways g and the total load. Most bicycle corners sit under 0.5 g, which is a lean of about 26°, and 45° is 1 g.
Table 1: lean angle in, g out.
| Lean | Sideways g (tan θ) | Total load (sec θ) |
|---|---|---|
| 5° | 0.09 | 1.00 |
| 10° | 0.18 | 1.02 |
| 15° | 0.27 | 1.04 |
| 20° | 0.36 | 1.06 |
| 25° | 0.47 | 1.10 |
| 30° | 0.58 | 1.15 |
| 35° | 0.70 | 1.22 |
| 40° | 0.84 | 1.31 |
| 45° | 1.00 | 1.41 |
| 50° | 1.19 | 1.56 |
| 55° | 1.43 | 1.74 |
| 60° | 1.73 | 2.00 |
The examples use speeds and radii we picked as scenarios. At 30 km/h on a 15 m turn you pull about 0.47 g sideways. On the Norwegian road standard’s minimum radii (see road bends and lean angle), 50 km/h on 60 m and 60 km/h on 125 m give 0.33 g and 0.23 g. For tight turns under 20 m, see roundabouts and hairpins.
Table 2: a few corners, in g.
| Speed, radius | Lean | Sideways g | Sideways m/s² | Total load |
|---|---|---|---|---|
| 20 km/h, 20 m | ≈ 8.9° | 0.16 | 1.54 | 1.01 |
| 25 km/h, 15 m | ≈ 18.1° | 0.33 | 3.22 | 1.05 |
| 30 km/h, 15 m | ≈ 25.3° | 0.47 | 4.63 | 1.11 |
| 30 km/h, 30 m | ≈ 13.3° | 0.24 | 2.31 | 1.03 |
| 35 km/h, 20 m | ≈ 25.7° | 0.48 | 4.73 | 1.11 |
| 40 km/h, 20 m | ≈ 32.2° | 0.63 | 6.17 | 1.18 |
| 40 km/h, 40 m | ≈ 17.5° | 0.31 | 3.09 | 1.05 |
| 45 km/h, 30 m | ≈ 28.0° | 0.53 | 5.21 | 1.13 |
| 50 km/h, 60 m (N100 minimum radius) | ≈ 18.1° | 0.33 | 3.22 | 1.05 |
| 60 km/h, 125 m (N100 minimum radius) | ≈ 12.8° | 0.23 | 2.22 | 1.03 |
Above 1 g: the total load
Sideways g is the pull across the bike. Gravity adds 1 g down, and the two combine into one load along the bike’s axis: gtotal = √(gsideways² + 1), which equals 1/cos θ.2 At 45° that is 1.41 g and at 55° 1.74 g. Below 30° the total stays under 1.15 g, so a normal corner feels close to normal weight and a fast one feels like the bike gets heavier.
Does weight matter?
Lean angle does not depend on mass: θ = atan(v²/(g·r)) has no mass in it, and the textbook says so for the same geometry: “θ does not depend on the mass of the vehicle.”1 Heavy or light, the same speed on the same radius gives the same lean. The force is what scales: F = m·g·tan θ sideways. In the scenario below, everyone leans 25.3°; the force follows the mass. The rider’s body and the frame can lean by different amounts; see the rider.
Table 3: the angle stays, the force follows the mass.
| Combined mass | Sideways force | Total force along the bike |
|---|---|---|
| 55 kg | 255 N | 597 N |
| 70 kg | 324 N | 759 N |
| 85 kg | 394 N | 922 N |
| 100 kg | 463 N | 1,085 N |
How much does 1 km/h change?
Speed enters squared, so small changes in speed matter more than small changes in radius at the same scale. The table shows the change in lean for 1 to 3 km/h more speed. A 5 m tighter line on a 30 km/h, 15 m turn adds 10.0°, and a 5 m wider one takes off 5.8°.
Table 4: the lean changes by a few degrees per km/h.
| Starting point | +1 km/h | +2 km/h | +3 km/h |
|---|---|---|---|
| 30 km/h, 15 m (25.3°) | +1.5° | +3.0° | +4.5° |
| 30 km/h, 30 m (13.3°) | +0.9° | +1.8° | +2.7° |
| 40 km/h, 40 m (17.5°) | +0.8° | +1.7° | +2.5° |
What Krengo shows
Krengo shows your lean angle in a corner. The g value follows directly from the first table, so you can read your lean as sideways g whenever you like. All g figures on this page are derived from the lean model.
Try it yourself
Put your own speed and radius into the lean angle calculator and read the g value off the first table. See also the glossary and how Krengo works. Learn new speeds on a quiet road with permission to ride there.
Frequently asked questions
How many g do you pull in a bike corner?
Sideways g equals the tangent of the lean angle: 25° is about 0.47 g and 45° is 1.00 g. These are model values derived from lean angle.
Does rider weight change lean angle?
Not in the model: θ = atan(v²/(g·r)) has no mass in it. The force scales with the mass, the angle does not.
What lean angle is 1 g?
45°. At that lean the sideways g is exactly 1.00, and the total load along the bike is about 1.41 g.
Sources
- OpenStax, University Physics Volume 1, chapter 6.3 “Centripetal Force”. Used for a = v²/r, F = m·v²/r, tan θ = v²/(r·g) and the statement that θ does not depend on mass. Read on 5 October 2026.
- Bourne, “The Physics of Riding on Track Bankings”, tracknut.ca (updated 12 January 2020). Used for gtotal = √(gl² + 1). Read on 5 October 2026.
The angles, g values and forces are Krengo’s own model values from site/calc.js, rounded to 0.1° and two decimals. The speeds, radii and masses are scenarios; the corner is treated as a flat circle and bike and rider as one body.