Approach and Departure angles are given special attention on vehicles intended to or marketed as serious
off road vehicles. All vehicles have an approach and a departure angle but larger angles are desired if a vehicle
is intended to go offroad.
The approach angle will be the degree between a forward line on a flat or level surface where the
front tires make contact with the ground and another line from that point to the part of the front bumper
that is likely to make contact with the ground or an obsticle first.
The departure angle will be the degree between a rearward line on a flat or level surface where the
rear tires make contact with the ground and another line from that point to the part of the rear bumper
that is likely to make contact with the ground or an obsticle first.
The approach and departure angles will determine the hieght of an obstacle or how steep of a hill a
vehicle can approach, climb over and exit or leave the obsticle without having the obsticle or the ground
scratching or draging the front or rear edge of the vehicle. This image shows a Range Rover with the
approach and departure angles. |
Image from www.landrover.com |
A vehicle may have an engine with more than enough torque to carry the vehicle up a
particular hill but if the start of the incline is not a smooth transition and the approach angle is too small to enguage
the hill then all of that torque will be useless for that hill.
Approach and departure angles are irrelevant if a vehicle has their front and rear wheels at the most forward and
rearward parts of the vehicle similar to how bicycles and motorcycles are designed.
The best ways to achieve higher approach and departure angles will be to implement certain measures when designing
the vehicle.
These measures are:
- A higher ground clearance obviously and it now common for luxury off road
vehicles to use air suspension to raise the ground clearance when the vehicle is
required to go offroad.
- Shorter overhangs which is the distance between the edge of the vehicle and the closest point of the tire.
- Designing the front and rear edges of the bimper round-ish and not with distinct edges. One example is the design
of the front bumper of the 2011 Porsche Cayenne.
Passenger vehicles still have to conform with certain design principles so it is common to see similarities
amoungst vehicles. For instance the front overhang is shorter than the rear in most vehicles but the rear overhang
usually has a higher ground clearance than the front.
The passenger bodystyles that would usually have good approach and departure angles for off roading will be
SUVs, crossovers and
pick up trucks. Vehicles where off roading takes a higher preference over passengers and attractive designs can alter the
above measures to achieve better approach and departure angles.
|
|
|
|