Driving technique - rocks

[mikem]

I've been on a couple of trips in the Sierra's recently that involved rocks.

http://www.mcune.com/gallery/BlueLakes07102004/IMG_2175

What is the best way to deal with a field of boulders?
Once I get started, I tend to keep going. I keep it slow and steady and let the ETC carry me over everything. This works great, but the truck bounces a lot and there is a high potential for damage.

Is it better to keep moving or try to take one rock at a time?

I'm driving a D2 with CDL , traction control and open diffs.

Thanks for your insight.

Mike

 

[Disco Mike]

Mike,
It is one rock at a time, between the spacing and different size of rock, the fact that they move around and you are slipping and sliding going through them, I would say, take it one at a time, forward speed is not the answer in a rock garden.
Take care, great pictures.
Mike J.

 

[Sergei]

Air down next time Around 16-18 psi. Everything else is correct, altough i never drove with ETC... Generally speaking braking is totally wrong on that kind of driving, and you better off controling speed via sticking to 1st or 2nd..
Also, i guess, ACE may have something to complain about when you driving over it.

 

[rover4x4]

well here where I am they are usually wet so wheelspin and momentum/luck are important. Air pressure and tire/tread etc are also key.

 

[GregH]

Nice pics!

Here's my 2 cents-

It's called crawling for a reason-slow and easy does it. I use plenty of left-footed braking in my truck that does not have ETC (i.e. right foot feathering throttle and moving by easing off brake with left foot). I use approx 15 lbs and MT tires in 1st/low.

Wheel and vehicle placement paramount. Remember diffs to right of center (except P38 are left of center) and try to minimize straddling rocks while also being careful of putting tires on too high of rock. When departing from said rock you may be resting (high-centered) on slider or, if rear tire going over, you may take out rear quarters or bumper if not protected.

However, without lockers or traction aids "sometimes" momentum is your friend in order to get over a particular obstacle.

The line you pick also may not be the right line for another rig with different wheel base, lift, tires, lockers or protection.

Crossing a rock garden can be both art and science and we are all learning and paying for our mistakes...

 

[Blue]

if rocks are bigger in diameter than your ground clearance, then do one at a time. Otherwise, just roll along nice and slow and smooth. You should have diff protection, so you need to be concerned about driving a rock into your spinning driveshafts, oilpan, steering links, etc.

 

[john]

Be like Caine on the rice paper.

 

[texmotoII]

You're killing me John. Just killing me.

David of Midland

 

[curtis]

LOL

"Snatch this pebble from my hand..."

 

[Ray Wallace]

Mike, that's a fantastic gallery! If I properly recall Bill Burke's training, take it sort of slowly, one rock at a time, when you get to the big 'ens try to use a spotter to minimize diff and other damage, and go "as slow as possible but as fast as necessary". Great to see you got the whole family out for a trek! Ray

 

[Kyle]

Slow enough so that every movement of the vehicle is predictable and controlable and always follow the path of least resistance. This applies to all situations and all vehicle setups. Take one rock at a time or multiple , depending on what kind of road it makes for you. Plot the course ahead of you and predict what affect each will have on the vehicle . Sometimes the worst looking path just happens to be the easiest one based on how level it keeps you or the traction it provides to all four tires. You want to picture those 4 tires at all times and where they will be along the path you have chosen..
If you are going so slow that you dont make an obstacle atleast you can adjust and try again without having to pay for a mistake. Going too fast can make you pay real fast in the form of vehicle damage. There is no shame in not making something the first few attempts and you usually learn much more about the vehicle and its capabilities by doing so. There is a time and a place for momentum but I consider it more a "Tactic" then a driving style.. By moving along slow and calculated I think you will find , that in the end , you will have had a much more enjoyable time and you will have come away with alot more knowledge about the vehicle you are driving , mods you may have added and how all of this intereacts with terrain...

Kyle

 

[curtis]

Damn Kyle, that was so true it struck straight to my soul. I'm getting all misty-eyed now

Seriously though, Kyle states it the way it is. Quite frankly the slow-and-go method has helped me at least try to overcome my inherent fear of rolling another Rover. The reduction in ego from taking it too slow is much better than what you get explaining why the roof is so short

 

[Ho]

you just need ticks hanging off your truck:

http://www.discoweb.org/wildwest/F1310004.jpg

and it's all good.

 

[Kyle]

Yes , and from time to time get a tick hanging on. OR , just keep it in the parking lot at Expedition Exchange.... Beside Ho's truck.................


Kyle

 

[p m]

Air down next time Around 16-18 psi.

... so that you can rip your tires' sidewalls sooner...

 

[GotRovr]

Mike

As I recall, you handled the Blue Lakes trail just fine, sans a few trail tattoo's.

From my limited experience, a rock garden will generally create 3 issues in any order, wheel slippage, high centering, and diff dragging.

What worked for me besides CDL and lockers was;
1) Setting tire pressure at 20 psi to increase wheel grip
2) Picking a line to run over the smallest rocks, spotter is essential
3) Keeping just enough firm pace or forward momentum without spilling coffee

Will

 

[Sergei]

... so that you can rip your tires' sidewalls sooner...

Eh? no, so you can get over obstacles better and not damage trail as much. If you got sidewalls that are gonna rip badly at this pressure - its time to get decent tires Even general grabber can handle it ok. In fact even 16-18 often is too much, but thats about limit where its safe - lower may get tyre off wheel.

 

[p m]

Eh? no, so you can get over obstacles better and not damage trail as much. If you got sidewalls that are gonna rip badly at this pressure - its time to get decent tires Even general grabber can handle it ok. In fact even 16-18 often is too much, but thats about limit where its safe - lower may get tyre off wheel.

Sergei, I have no idea what are you talking about.

He asked about driving over the rocks - so trail damage is somewhat out of question here.
You can get a more traction on the rocks while airing down - at a clear expense of increased risk of losing a bead or ripping a sidewall.

Decent tires? I've destroyed three 35" BFG mud-terrains on the rocks (general grabber ain't even close), for a single reason - aired down. And, the only reason for airing down was not to get more traction, but to ease driving over tens of miles of washboard.
16-18 too much? I never aired down to less than 20 - on C-rated tires, with 35psi max, or 25 - on E-rated tires. Aired down to 25, I've ripped a sidewall of a perfectly stout Futura Enforcer in Colorado. Guess what, a single tire store in Ouray, CO, doesn't have a whole lot of 245/75R16s...
And I haven't ever been accused of being a throttle jockey, either. All these occasions happened at tire speed of a fraction of a turn per second.

 

[Sergei]

Humh. On what trail in Ouray?

I am not accusing you - i just truly dont get it.

 

[p m]

Poughkeepsie gulch. For comparison's sake, I have driven it two years before that trip, on stock Michelins at street pressure (which I keep at 35f/40-45r) - and they came out unscathed.