Angles and Clearance

Sure you have driven your rig many many times, but how much time have you really spent looking at it, or more specifically UNDER it? Getting the most out of your rig means picking lines that will work with it's strengths and weaknesses and knowing what it will do under any situation. 

• Approach angle:  This is the angle that an obstacle can be at without planting your bumper into it.   
• Breakover: If your breakover angle is too low you will get stuck on the belly of your rig as you come over the obstacle.   
• Departure angle: The angle to your rear bumper, hitch or whatever the low point is.  This is usually less than your approach angle, so it's common to think you are in the clear and suddenly find yourself suspended by your back bumper with your back tires in the air.

This person barely avoided planting the front bumper into the sand.  His departure angle, on the other hand, was worse so his trailer hitch added yet another gouge to the rock face. 

This driver knows that his spring mounts will hang up on the log if it goes under his rig, so he puts his tires on the log and drives down it instead.

• Belly Clearance: This determines your breakover angle, and is also important to know for rocks and berms that go under your tires.  You need to look at your frame, transfer case, and anything else that hangs down.  Most rigs have a lot of vulnerable parts under the belly so pay close attention to their location.
• Axle Clearance:  Depending on the design of your axle and suspension you will have different low points. Pay attention to shock mounts, suspension arms, and steering components.