For many of the less adventurous spirits out there, a bumpy, muddy, rocky road would be a driving nightmare. However, for us, the rougher the road the better. In fact, the way we see it, no road is best of all. Throw in an obstacle or two and it’s game time!
Many off-roaders enjoy just being outdoors, while others live for the physical and technical challenge that driving through certain terrain brings. While the thrill and adventure is what we all collectively seek, there is a “geekier” side to the sport and the physics of what we do should be understood. Many of us call it instinct, but let’s give ourselves credit for being as smart as we are. Let’s get scientific for a moment and look at some of the basic physics of what we do.
Traction
The most important thing to consider in off-roading is traction, or the grip your tires have on whatever surface you're driving on. In our sport, by definition, traction is “the action of drawing or pulling something over a surface, especially a road or track, the grip of a tire on a road or a wheel on.”
Traction is affected by the type of tires being used, their size, and their air pressure. Depending upon where you are of off-roading, the type of tires on the vehicle allow you to maintain control on the surface you are driving on.. For example, some tires have bigger treads that are meant to give you better grip when driving through muddy terrain. Engaging your four wheel drive gives each of the tires better grip and allows control on the surface. It might seem counter-intuitive, but lowering the air pressure of your tires increases your control and traction as more of your tire surface is gripping onto whatever you're driving over.
Momentum
Do you remember sitting back in school and learning about motion and momentum? Momentum factors greatly into your off-roading. Momentum which is the mass of your vehicle multiplied by its velocity is what gets you to the top of the hill or over the obstacle. The one thing, for the most part, that you can control is your speed. Remember the mass of your vehicle is fixed. It is the friction with the ground coupled with the force of gravity that kills your momentum. Maintaining momentum when overcoming obstacles or getting up the steep hill is one of the most important things to factor in. Often times, getting yourself into a bad jam was caused in part by not being able to maintain movement forward or backward.
FInally A Use For Geometry
We always wondered when high school geometry would factor into everyday life. Having the understanding and being familiar with the three most important angles on your car will help save you from getting stuck. The three most important angles are, the approach angle, departure angle and break-over angle. Taking into consideration traction, momentum, and now these angles will help you get through and over any obstacle. The approach angle is the maximum angle from the ground that a hill or object can have that the front of your vehicle is moving towards. When approaching a hill or an obstacle, check to see if your bumper will hit before your tires can reach it. If so, you might as well be driving into a wall. Anything that is too steep should never be attempted. The same goes for the back of your car. The rear bumper and wheels account for the departure angle. Once you go up, you must come down, so before attempting a hill or obstacle, you need to know the clearance you have so you can get past the obstacle without destroying the underside of your car. This is a simple measurement and is known as the break-over angle of your vehicle. Measure the space between your tires and the center of your vehicle. Misunderstanding or miscalculating the break-over angle of your vehicle could have you sitting scratching your head while you wobble back and forth! The good news, you don’t have to be a mathematician to measure your car's angles. According to one expert source we referenced for this blog they state, “take a long, straight object such as a yardstick, broomstick or board, and place one end where the front of your front tire touches the ground. Lift the other end up until it hits the lowest point of the front of your car. The angle of the object is your approach angle. You should never attempt to go over a rock higher than the point at which the board makes contact with your bumper.” This is what we consider the best strategy if you are unsure of your ability to tackle an obstacle.
What Happens When You Get Stuck
Math and science are great, but let’s face it, we are out here to have some fun and take on the challenges that each terrain brings us. At times the thrill or just the excitement gets the better of us. Understanding the science behind off-roading is beneficial, but what happens when you still get stuck? Having great recovery gear with you can always save the day. GearAmerica's Ultimate Recovery Kits include everything you need to get unstuck and get back to doing what you went out to do even if you didn’t bring your calculator!