Motorcycle Cornering Speed Calculator
Calculate the maximum safe cornering speed for a motorcycle based on radius, lean angle, and road friction.
When a motorcycle corners, centripetal force must be balanced by the lateral grip of the tires. The maximum speed through a corner depends on the corner radius, road surface friction, and lean angle.
The formula: v = sqrt(r × g × mu × cos(lean) + r × g × sin(lean))
Simplified for a flat road: v = sqrt(r × g × mu)
Where:
- v = maximum speed (m/s)
- r = corner radius (meters)
- g = 9.81 m/s²
- mu = coefficient of friction (tire-to-road grip)
Friction coefficients (mu):
- Dry tarmac, sport tires: 0.9–1.1
- Dry tarmac, touring tires: 0.7–0.9
- Wet tarmac: 0.4–0.6
- Gravel/loose surface: 0.3–0.5
- Painted road markings: 0.3–0.5
Worked example:
- Corner radius: 50 m, dry road (mu = 0.85)
- v = sqrt(50 × 9.81 × 0.85) = sqrt(417) = 20.4 m/s = 73 km/h
Safety margin: Real-world riding always has unknowns — road camber, surface contamination, tire temperature, vehicle loading. Ride at 70–80% of the calculated maximum. Lean angle naturally increases as you approach the limit — the bike geometry handles this, but smooth throttle and no sudden inputs are essential.
Corner radius estimation: A tight hairpin is 5–15 m. A sweeping mountain bend is 50–200 m. A motorway on-ramp is 100–300 m.