Dune Crossing Tutorial and Techniques

[Frederic]

Different ways of crossing sand dunes

Throughout the Carnity Offroad briefings you might have heard the terms "straight up and straight down", "side sloping", or "criss-crossing", and these are basically different techniques that we use in desert for crossing the sand dunes. 

Each come with its own risks and by learning and understanding the technicalities behind them i hope we can all learn faster and get more confidence in executing them. I hope below tutorial gives a more clear understanding on the subject and we can use it for future reference.

1) Straight Up - Straight Down

Carnity Offroad Level: Newbie and Fewbies

Description

This technique is one of the very first we learn to apply when learning offroading. The trick is to approach the dune straight up with "JUST" enough momentum to make it through, but not too much to damage bumpers or cause a jump.

One should always take into account the resistance that the sand offers based on different areas, and even more on different seasons.

Most sand dunes have two sides

- The windward side, which is the side where the prevailing wind blows on, and can be recognized by the wavy lines of the sand. This is the side where we ride on because the sand is more compacted and firm to drive on. 

- The slip-face side, this the softer backside (smooth side, no lines) of the dune which is generally not recommended to climb on, but this technique can later be learned as you advance through the off-road levels (slip-face attack).

How to tackle

It is advisable to start off at the bottom of the dune with applying a decent amount of power, and start letting go of the gas once you have climbed 75% of the dune. By that point the momentum should carry you further, and as soon as the car front wheel touches the crest, leave the gas completely or apply a bit of gentle braking when needed, to let you slide on other side of the dune safely. In fact the perfect technique is finding that right amount of momentum that you don't even need to apply brakes on the other side. Some gentle blips of throttle can help at the top to push you over the edge, as you learn and master this first step.

If you run out of momentum going upwards to cross the dune, do not worry or panic, this is called a REFUSAL. Gently reverse and slowly come back in a straight line as you have climbed up. Announce on the radio that you have a refusal. Reverse up far enough so you can take a second attempt but this time with a bit more momentum. 

Risk Level:  Low to medium. Approaching too slow will increase refusal and might cause stuck at the crest. Approaching with excessive speed might damage the bumpers or cause a vehicle to jump. Apply gentle throttle and slowly increase after learning.

Take note that every dune is different and each approach will need to be made slightly different in terms of speed. 

Associated Risks: If you approach the dune too fast, more likely you will cause the bumper damage because your reaction time will be reduced substantially at very high speed.

 

2) Side-Sloping

Carnity Offroad Level: Fewbie and upwards

Description

This technique is very fun and addictive, but it needs to be executed with a clear mind and a good experience on the behavior of the car. That is the main reason why this technique is only used from Fewbie level onwards.  It is very critical to understand how gravity works and as we always says: " DO NOT FIGHT GRAVITY ". this applies to this technique most of all. 

When you approach a dune that you want to side-slope on, you need to carry enough momentum to get you through. This does not necessarily mean FULL throttle, because that depends on the type of dune. As soon as your car is on an incline, it will have the natural tendency to try to come down. The more momentum you carry, the further you will get. It is extremely important that you do not fight this by going higher up the dune at that point, but to steer down in a smooth way.  Braking at this point is also very dangerous.

While doing side sloping try to choose smooth path as possible and avoid stepping on rock, bushes or bumps that can bounce you and disturb the whole balance and tip you off or result in dangerous fish-tailing or tire pop-out at high speed.

EVERY MOVEMENT OR ACTION YOU DO WHILE SLIDE-SLOPING NEEDS TO BE DONE IN A SMOOTH WAY, SUDDEN BRAKING OR EXTREME STEERING CAN LEAD TO ROLL-OVERS.

Best practice: Always visually mark the entry and exit of the dune that you wish to do side sloping on. Stick to the initial plan as far as possible and exit safely. If you are new to this, then watch and observe how others have done before and try to replicate that as much as you can.

The best thing to keep in mind is to think about "HALF MOONS" What i mean with that is that you should never make 90° turns during any kinds of these activities, but make smooth half moons during approaching dunes or crossing them.

Risk Level: Medium. With proper training and guidance you can eliminate the risk of a roll-over for 95%, but one should always be aware of the risks involved and take all measures possible to minimize these. Keep both hands at the steering wheel and your full attention on the view ahead. Do not get distracted !

Associated Risks: If your vehicle is lifted more than 4 inch of OEM stock height then your 4x4 center of gravity will be less, and this will increase the risk of roll-over or flip by 50%. Same goes for bouncy (non-standard/rated) suspensions.

 

3) Criss-Crossing

Carnity Offroad Level: Fewbie and upwards

Description

Criss-crossing is the art of riding the ridge of the dune and crossing over to the other side. Also here it is vital to understand that the approach towards the ridge, as well as the crossing over needs to be done in a smooth, half moon way.

So basically you approach the dune along the length, you can stay on the ridge for as long as you want, but don't lose momentum at this point, or you will be crested lengthwise in the exact middle.

Now the trick is to choose the right point at which you cross towards the other side. This feels scary at the beginning, but soon you will get the hang of it, and cross ridges without panicking at all. Make the criss-cross movement again in a half-moon method as seen below. 

Below picture shows the right and wrong way to criss-cross a dune. On the left side you will see that the approach is smooth and as soon as you cross over to the other side you gently steer down. Braking at this point is again very dangerous.

In the right-side scenario, the angle of approach is very sharp, and during higher speeds this can result in a roll-over. 

EVERY MOVEMENT OR ACTION YOU DO WHILE CRISS-CROSSING NEEDS TO BE DONE IN A SMOOTH WAY, SUDDEN BRAKING OR EXTREME STEERING CAN LEAD TO ROLL-OVERS. 

Risk Level: Medium. With proper training and guidance you can eliminate the risk of a roll-over for 95%, but one should always be aware of the risks involved and take all measures possible to minimize these. Keep both hands at the steering wheel and your full attention on the view ahead. Do not get distracted !

Associated Risks: If your vehicle is lifted more then 4 inch of OEM stock height, then your 4x4 center of gravity will be less and this will increase the risk of roll-over or flip by 50%. Same goes for bouncy (non-standard/rated) suspensions.

 

4) Hill Climbing

While this technique is not immediately necessary to cross dunes, climbing a mighty big dune will bring some fun and adrenaline in the equation. At first, you might feel intimidated and not sure if your car can handle this. With the right techniques at hand you can at least make a safe attempt and see how far you can get. This technique can be practiced from Newbie level onwards on small hills, and later you will learn to approach taller dunes from Fewbie level and up.

Again it is extremely important to make a smooth "half-moon" circle at the top. If you run out of momentum and come to a standstill, DO NOT attempt to make a turn, but put your car in 4LO, and slowly reverse down the dune while keeping your wheels straight. The low gearing will help you in keeping that slow pace.

As you begin to learn this, it's always advisable to make a smaller U-Turn to learn how your car reacts and how your mind reacts when you take the first turn on top of dune. This needs to be done with confidence and without any doubt or fear, so that you don't brake on top and do the complete U-Turn without braking and in a very smooth manner. Practicing on small U-Turn will build your confidence and after 5-10 small U-Turn attempt you can try higher and higher by understanding your vehicle dynamics and limitations.

Risk Level: Medium. With proper training and guidance you can eliminate the risk of a roll-over for 95%, but one should always be aware of the risks involved and take all measures possible to minimize these. Keep both hands at the steering wheel and your full attention on the view ahead. Do not get distracted !

Associated Risks: If your vehicle is lifted more than 4 inch above OEM stock height, then your 4x4 center of gravity will be less and this will increase the risk of roll-over or flip by 50%. Same goes for bouncy (non-standard/rated) suspensions.

 

Safety of all offroad enthusiasts is the most important thing.  This is an extreme hobby that brings confidence, thrills, and people together as a family. We can only do whatever we can to make all safety instructions clear and concise but in end it's up to the offroader behavior to understand all risk and associated risk involve and enjoy safely.

Open for any questions or comments !

[Frederic]

 

[adildbx]

Thank you @Frederic  ..very informative

[Julien V]

Thanks Fred for this work. Really awesome.

[Gaurav]

Well done @Frederic for taking so much time to share this great off-road knowledge.

Very well explained and documented with perfect diagrams and videos.

Only thing I like to add for all new offroaders, learn and follow above instructions to the max but never fight the gravity.

If you had a bad feeling for any side sloping, criss crossing attempt, exit safely and make another attempt rather than fighting the gravity. Small deviation of track can also cause lot of difficulty and push the car to the soft patch, in that case simply accept the defeat and exit down without fighting with mother nature. Even experienced offroader do have refusal and repeat without any hesitation, that's the real fun and challenge of offroading.

[Rahimdad]

Very well documented @Frederic. Very descriptive but for some it takes time to perfect the technique, take your time and remember safety is paramount.

[Shamil]

this is very well put @Frederic. A good guide for newbies to understand the technical details of dune bashing. I will refer this thread to newbies who are interested in understanding the dune bashing techniques.

Edited December 8, 2019 by Shamil

[Chirag S.]

Super

On 12/7/2019 at 1:15 PM, Frederic said:

 

Wonderful

[Asif Hussain]

Criss Crossing

Don't try this without experience it requires lot of practice.

[Jun Zamora]

Thanks Fred , very challenging. !