Breakover angle is the maximum possible supplementary angle (usually expressed in degrees) that a

vehicle A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), ...

, with at least one forward wheel and one rear wheel, can drive over without the

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics), a teenaged super villainess in the Marvel Universe * Ape-X, a super-intelligent ape in the Squadron Supreme universe *Apex, ...

of that angle touching any point of the vehicle other than the wheels.Division of the Federal Register, United States: ''The Code of Federal Regulations of the United States of America'', page 447. U.S. Government Printing Office, 1979. SAE J689: Cancelled AUG 2009 Curbstone Clearance, Approach, Departure, and Ramp Breakover Angles--Passenger Car and Light TruckSAE J1100 NOV 2009 Motor Vehicle Dimensions This definition is contingent upon the wheels being in continuous contact with the supporting surface(s). Breakover angle differs from

ground clearance Ride height or ground clearance is the amount of space between the base of an automobile tire and the lowest point of the automobile (typically the axle); or, more properly, to the shortest distance between a flat, level surface, and the lowest p ...

, which is the shortest distance between the ground and lowest point on the vehicle.

Relevance

Breakover angle is a relevant performance metric in many common vehicle scenarios, including: *

Off-roading Off-roading is the activity of driving or riding in a vehicle on unpaved surfaces such as sand, gravel, riverbeds, mud, snow, rocks, and other natural terrain. Types of off-roading range in intensity, from leisure drives with unmodified vehicl ...

. * Loading a vehicle onto a higher surface with a ramp. * Going over raised railroad crossings. * Going over

speed bump Speed bumps (also called traffic thresholds, speed breakers or sleeping policemen) are the common name for a class of traffic calming devices that use vertical deflection to slow motor-vehicle traffic in order to improve safety conditions. Varia ...

s * Going over linkspans and

ferry slip A ferry slip is a specialized docking facility that receives a ferryboat or train ferry. A similar structure called a barge slip receives a barge or car float that is used to carry wheeled vehicles across a body of water. Often a ferry intend ...

s If a vehicle drives over a breakover angle larger than what it is capable of clearing, the vehicle will contact the apex of the angle, which will quite likely prevent the vehicle from continuing any further in its direction of travel, possibly even completely immobilizing the vehicle.

Calculation

Assuming no tire deflection, and assuming an ideal breakover angle scenario (two flat surfaces coming to a point, a vehicle with the lowest point of the chassis located at its midsection, etc.), an ''approximation'' for the breakover angle of a vehicle can be calculated as follows:

\text_ = 2 \cdot \arctan\left(\frac\right)

References

External links

*HowStuffWorks
The Physics of Off-Roading
{{carDesign nav Automotive engineering

Relevance

Calculation

See also

References

External links