Trail Ratings

You'll notice on my trip reports I give a trail rating for the run, a number that is supposed to give you an idea of how setup your vehicle has to be in order to run the trail without difficulties.  I have based those numbers on what other entities such as the ASA4WDC and local 4 wheel drive clubs rated the trails.  The problem I see is I have been running a lot of trails rated 4.5, and some are a walk in the park while others are a serious challenge, and at the same time other vehicles on the same trails are struggling even more, or worse yet breaking parts and denting sheet metal.  Part of this may be because when those trail ratings were made no one even dreamt of the obstacles we would be attempting 5-10 years later. So how do you, the person reading at home, know if your going to try the same trail will you come out unscathed or is there a very likely chance for body damage?   A question I am hoping to answer.  

The trail rating I have come up with will break up vehicles by weight.  The light category would be Jeep Willy's or Samurai sized vehicles, medium would be Jeep/Toyota sized vehicles and Large would be the full sized pickup/blazer type vehicles (assumes stock wheelbase).  Weight is important because the heavier the rig the more strain you put on the running gear when running a trail.  Also a lighter vehicle may have better break over angles due to it smaller size, ground clearance may be better due to smaller axles, a narrow body makes some obstacles non-obstacles and it's generally easier to extract a lighter vehicle.  The trail rating also assumes an experienced driver and dry conditions.  The goal is if your rig has the recommended equipment you should be able to traverse the trail without having to take bypasses (if any exist), stack rocks, use a hi-lift or break major components.  Now I know what your thinking, some of your friends can bend a crowbar in a sandbox so how can I say they won't have major breaks.  There's always a chance to break, parts fatigue and we push most components far beyond their original design parameters, but if you inspect your vehicle after runs, maintain it religiously and tackle trails you are ready for (both skill and equipment wise) you can minimize breakage.  Over the past two months I have managed to run over 16 of Arizona's hardest trails without breakages, sometimes 3 or 4 trails in a weekend, so it is possible if you're properly equipped.  One final note, the recommended equipment is additive, so everything listed for a 1, 2, 3 and 4 rated trail is recommended to run a 4 rated trail. Also, if you extend your wheelbase you will need to bump up the tire size to keep underbelly clearance. 

Most Forest Service Roads

Appetizer

Crown King (Back Way)

Tip Top Loop

Reno Pass

Log Corral Trail

Lower Firebird

Powerline Trail

Raw Deal

Ruby Wash (Optional Obstacles)

Trail 42 (Changes greatly depending on rainfall)

Upper Woodpecker

Bumble Bee Creek

Can Opener

Judgement Day

Terminator

Predator (Used to be a 4)

Rocker Panel Pass

Axle Alley (Most will need to winch at the end, used to be a 5)

Bad Medicine

Highway to Hell (Horribly stacked, from what I heard,  now a 3, was  a 5)

Lower Woodpecker

Lost World (Taking all the hard lines, there are bypasses)

Martinez Canyon

Payeatt Draw

Squeeze Rock

Upper Firebird

Anaconda

Armageddon (Stacked pretty bady, is currently closed)

Chaos

Hysteria

Jawbreaker

Landslide (Getting stacked, heard it was getting easy)

Lower Morningstar

Overdose

Woody's Wash (was a 5, 1st obstacle getting stacked)

6th Day

Annihilator

Collateral Damage

Die Hard

Matrix

Pet Cemetary

Resolution

Skullcrusher

Twisted

Sanitarium

What was wrong with the existing trail ratings? Here's my take:

 An example taken from a local 4 wheel drive club's web page:

4.5 - These trails cross extremely rugged terrain with very steep inclines, large boulders, and potentially dangerous situations. These trails require modified vehicles, including lift, lockers, and over-sized tires. A High level of Off-Road driving skill is required. There will likely be paint damage, possible vehicle body and/or mechanical damage. There are possibilities of rollovers. Winches are recommended.

Ok, so lets say you take your stock vehicle, install some aftermarket bumpers so you can use a hi-lift from either end, you add some thick steel skid plates over the rocker panels and in strategic positions underneath, for added clearance you install a 5" lift kit, a winch for recovery, lockers front and rear, lower ring and pinions to help turn the tires, some aggressive 35" tires, a tool box with your tools along with some spare u-joints and axles. Sounds ideal right?   Herein lies the problem.  You just added another 1000 or more pounds to the weight of your vehicle, not to mention your tires won't slip anymore thanks to those lockers so the weak link becomes your axles.  You just did everything the trail rating recommended and it increased your chances of breaking something.  I don't know about you, but when I want to do some wrenching I do it in the garage.  When I go out four wheeling I want to run the trail without having to modify the trail or force my way thru obstacles.  

I also have never seen a single trail rating system yet that mentions gear reduction systems (gear sets, aftermarket t-cases or dual t-case).  If you've never seen a vehicle crawl around with a 100:1 or higher crawl ratio you are missing out on a whole new dimension in rock crawling.  The super low tire speeds allow you to hunt for traction on rocks without having to use the gas pedal giving the driver an amazing amount of control, and that control can keep drive train components alive.