km/h
m
Result
Lean angle (thin-tyre theory)52.7 °
Lateral acceleration1.31 g
How it is calculated, with your numbers
- Speed in m/s
v = speed / 3.6100 / 3.6 = 27.78 - Lateral acceleration
ay = v² / (g × r)27.7778² / (g × 60) = 1.31 g - Lean angle (thin-tyre theory)
lean = atan(v² / (g × r))atan(27.7778² / (g × 60)) = 52.7 °
Working uses the metric units the formula is written in.
- speed Speed (km/h)
- r Corner radius (m)
- v Speed in m/s
- ay Lateral acceleration
- lean Lean angle (thin-tyre theory)
What it means
To go round a corner, the combined centre of mass of bike and rider must lean so that gravity and the cornering force balance. For a perfectly thin tyre the angle is the arctangent of v² / (g × r), the lateral acceleration in g.
Real tyres have width, so the contact patch moves out as the bike leans and the bike needs a few degrees more than this; hanging off the bike reduces the lean the motorcycle itself needs. Around 1 g of grip (45°) is near the limit of good road tyres; racing tyres manage more.
Assumptions and limits
- Steady-state corner, level road, thin-tyre approximation.
Sources
- Cossalter, V., Motorcycle Dynamics, 2nd edition, 2006.