Lean Angle Calculator

Cornering on a motorcycle works by leaning the bike into the turn so gravity and centripetal force balance each other through the tire contact patch -- the required lean angle comes directly from the physics of circular motion, tan(angle) = v^2 / (r x g), where v is speed, r is the turn's radius, and g is gravitational acceleration. Because speed is squared in this relationship, small increases in speed require disproportionately larger lean angles to hold the same turn radius -- doubling your speed through a corner roughly quadruples the centripetal force your tires need to generate, demanding a much steeper lean. A tighter turn radius has the opposite, milder effect: tan(angle) scales inversely with radius, so a smaller radius directly increases the lean needed, but not as steeply as speed does.

The Max Safe Lean Angle output represents the theoretical limit set purely by available tire grip -- the maximum lean angle where the tire's friction coefficient can still supply enough sideways force before the tire slides, tan(max angle) = grip coefficient. Comparing the Required Lean Angle to this limit (the Safety Margin output) shows how close a given speed and radius combination is pushing the available grip. This is an idealized physics model: real-world lean limits are also constrained by ground clearance, tire profile, suspension geometry, and rider skill, which this calculator does not account for.