In an Emergency, when you need a tow strap or winch controller, you usually need it quickly. They should be somewhere the driver can reach quickly while in his/her seat. You certainly don’t want to have to open the back and sort around trying to find them. When alone, a good place is on the floor in front of the passenger seat. If you have a passenger, on the floor behind the passenger seat.
DRINKING ON THE TRAIL
Participants on our runs must follow California Laws on alcohol at all times. The law forbids operating a motor vehicle while under the influence and forbids drinking alcohol at any time while in a vehicle by either a driver or passengerwhether moving or parked. No open containers are allowed by law. The law and our Rule do not distinguish between public or private property or the driver or passenger..
Participants should consume their alcohol in camp or at home, after the run.
We do not allow drinking during our Runs except we do allow adults to drink no more than one beer during lunchbreak while outside the vehicle.
We do object to participants (including passengers) having more than one beer, or other alcoholic drinks during the Run. If they insist on drinking on a run, they will be asked to leave the Run and not go on future runs with the Group.
Like driving anywhere else, driving a vehicle off road while under the influence endangers the person drinking, other occupants of his/her vehicle as well as others on the trail.
Anyone, whether Driver or Passenger who refuses to follow this policy will be asked to not attend JustRuns Events/Runs.
My wife prefers narrow (Pizza Cutter) tires (9.50 or 10.50) on her Jeep and she usually gets better traction than I have on my Jeep using wide tires. (12.50). She has better luck in both deep sand and on loose dirt. The article below seems to agree that for most off-road situations we often encounter, narrow tires are better. That is even though they don’t look as “Macho”. – Roger
Tire Selection for Expedition Travel: The impact of tire width on traction
Article Type: Position Paper, White Paper
By: Scott Brady, Expedition’s West
Position: A tall, narrow tire is a superior choice for all off-highway surface conditions with the exception of deep, soft sand or mud.
This is an empirical summary of my position. The supporting details of this argument are contained in the body of the document. The start of my study came as a result of asking the critical question. What is better for most trail surfaces; a wide or narrow tire?
This initially led me to research the physics of tire traction, which is mostly related to dynamic friction as the vehicles are not just parked on a surface trying to maintain a static state. There has been some research on the subject related to performance vehicles and race cars, operating on highly tactile surfaces, and running at high speeds (and subsequent heat generation), but there was no significant research done for off-highway vehicle operation. So I spent several months researching the subject, testing the logic and formulating a position. Why a position, and not a conclusion or “law” of tire performance? For me to proclaim a conclusion would require much greater testing volume, samples, variables etc., which time does not allow. So, the following is my position.
When driving off-highway, the performance of a vehicles tires is influenced by the elements of friction as related to the following items: Adhesion, momentary molecular bonding, deformation and mechanical keying (Haney, 2003). Where a race car operates on a highly tactile surface, which allows wide, even smooth tires to perform exceptionally (due to adhesion and bonding), an off-highway vehicle operates in the exact opposite environment, with minimally tactile surfaces. Rocks, dirt ledges, dusty boulders, highly irregular surfaces, sandy washes, etc. occupy the fourwheeler’s environment. Surfaces that do not provide high adhesion rates or momentary bonding. However, these surfaces are highly irregular, which does provide the opportunity to take advantage of mechanical keying and deformation. These traction elements require high contact pressure, coupled with low air pressure to get the tire to flex with the terrain. A wide tire distributes the vehicles weight over too large of a surface, preventing deformation from occurring at the same rate as a narrow tire with the same pressure (force). A narrow tire will hold better than a wide one by keying to the surface aggregate due to the greater vertical force.
It is important for me to note that this document is NOT about reducing tire air pressure “airing down”. Airing down provides its own performance benefits which are not covered in detail in this paper. For all examples assume that the wide and narrow tire are both at 15psi for the trail.
While the coefficient of friction (Ff = Cf x Fv) is linear and not affected by width (on a perfectly smooth surface, traction is consistent despite width), it is the variability of the road surface conditions off-highway that improves traction for a narrow tire. The greater the contact pressure, the greater of effectiveness of the friction elements of Deformation and Mechanical Keying. A narrow tire also presents less rotating resistance on a soft surface, like shallow mud, snow and sand. Additional performance is gained by the assumption that most vehicles can fit a taller tire if it is narrower, which provides greater axle clearance. Final arguments are made for the benefits related to reduced rotating mass and unsprung weight.
The argument is further bolstered by the assumption that a taller tire can be fitted to the vehicle if it is narrower. For example, a Toyota Tacoma can fit a 33×10.5 with 2″ of lift, but not a 33×12.5 with the same wheel off-set, suspension, etc. A taller tire allows the driver to air down further (maintaining sufficient ground clearance), increasing tire deformation on technical terrain and increased flotation on surfaces with low shear resistance (like sand).
The argument assumes that the surfaces encountered off-highway are not typically highly tactile, like concrete or asphalt, but are irregular, and loose, with poor surface condition (either dusty, muddy, wet, etc.)
This article is specific to heavy expedition vehicles with nominal lift and stock engines (as is desirable for extended travel reliability). The article is NOT about 1,500 lb. sand rails with high HP motors, or other competition platforms with one dimensional surface conditions.
Friction: (Mech.) The resistance which a body meets with from the surface on which it moves. It may be resistance to sliding motion, or to rolling motion. [1913 Webster]
Adhesion: Intermolecular forces that hold matter together, especially touching surfaces of neighboring media such as a liquid in contact with a solid.
Momentary Bonding: The brief molecular connection of two surface elements under heat, pressure or mixing.
Deformation: The change in geometric size, shape, form or position due to force.
Mechanical Keying: The interlocking of surfaces
Reading a flotation tire: Example LT 31×10.5 R15 C
“LT”= Light Truck. Intended to be used on a heavier vehicle, with a higher GVWR than a typical passenger car.
“31”= The tire height, represented in inches.
“10.5”= The tire width at the section (widest point of the carcass), represented in inches.
“R15″= Indicates the tire is a radial and has a rim size of 15 inches.
“C”= The load rating of the tire. It can also be D, E, etc. The higher the letter, the greater the load carrying capacity.
Reading a metric tire: Example LT255/85 R16/D 119Q
“LT”= Light Truck Tire
“255”= The section width in millimeters
“85”= The aspect ratio. Expressed as a percentage of the section width (so 255*.85=216mm). The result is the height of the tires side wall. To determine the overall height of the tire, the following equation is used [(side wall height)*2+(rim height)=total tire height]. For the example tire the equation reads [(216*2)+406=838mm] Note: A 16” wheel is 406mm tall
“R”= Radial Construction
“16”= Rim diameter in inches
“D”= Load Range . Indicates ply rating (example tire is 8 ply), and load pressure, or the recommended tire pressure at maximum load (example tire is 65psi) Available Chart= http://www.tiresafety.com/size_class/size_nav4b.htm#plyrating
“119”= Load Index, which is the load carrying capacity of the tire (example tire is 2998 lbs.) A good load index chart is available here http://www.tiresafety.com/size_class/size_nav2.htm
“Q”= Speed Rating (example tire is 95mph). Available Chart= http://www.tiresafety.com/size_class/size_nav2a.htm
Important note: For the sake of the following details, assume that the test vehicle is 5,000 lbs., and a narrow tire would be considered a 33×10.5 R15, and a wide tire would be considered a 33×12.5 R15, both run at 15psi for trail use.
The benefits of a narrow tire:
The Argument: A tall, narrow tire is a better choice for all off-highway surface conditions with the exception of soft sand, snow and soft mud that’s depth exceeds 110% of the vehicles minimum ground clearance. Here is the explanation.
• Contact Pressure: Contact pressure is expressed as the vehicles curb weight distributed over the contact surface of four tires. The contract pressure is not equal to all four tire road surface contact points as the vehicles weight is not perfectly distributed. To ease the description, let’s assume that the test vehicle weights 5,000 lbs and has a perfect weight distribution. Each of the vehicles four tires would be creating 1,250 lbs. of vertical pressure on the terrain. Let’s assume for the sake of this example that the vehicles tires are 10” wide, where the load and tire pressure results in a total surface area of 30 sq. inches. The total pressure per square inch (without equating the secant) would equal 40 lbs.
• Rolling Resistance: A narrow tire presents less rolling resistance on improved surfaces, increasing fuel economy and performance.
• Frontal Resistance: This is another key benefit of using a narrow tire. When driving through mud, snow and sand a narrow tire presents less surface area to the medium. A narrow tire will cut easier through mud, snow and sand than a wide one (due to resistance). The best example of this is when turning in sand. When the front tires turn, they present a wider surface to the sand. You can feel speed reduce immediately when a turn is initiated because of the resistance.
• Rotating Mass: A narrower tire weighs less than a wider one of the same height. The difference in weight between a 33×10.5 and 33×12.5 is about 5 pounds, coupled with the narrower, lighter wheel, the affect on rotating mass is significant. A lighter tire and wheel is easier to accelerate and stop.
• Size Fitment: All things being equal, a narrower tire is almost always easier to fit with less fender trimming and total suspension lift that a wider tire of the same height. Wider tires affect turning circle, compression travel (which needs to be limited by lowering the bumpstops, etc.).
Practical Application: I find a good rule is to use as tall a tire as possible with the same section width as the widest tire available from the factory for that particular model. That way the tire will compress into the wheelwell designed for that width, without rubbing due to width. Example: I was able to fit my Tacoma with a 33.4”x10.5” tire with only a 1 ¾” lift. A 33×12.5” tire would require additional trimming, less wheel offset and lowered bumpstops.
• Weight: Without making this an article about suspension, one of the jobs of a properly engineered suspension is to control the cycling of unsprung weight, which is comprised of the axles (control arms, knuckles, etc. in an IFS), tires and wheels. The lighter those assembly’s are, the easier it is for the suspension to control it, improving performance.
• Airing Down: This is another critical concept highlighting the advantage of a narrower tire.
As quoted from Sahara Overland, a Route and Planning Guide by Chris Scott (2004, ISBN: 1-873756-76-3):
Negative Effects: Nothing in the world is perfect, so there are some downsides to using a narrow tire…
The Benefits of a Wide Tire:
The flotation tire provides three benefits. Greater high speed handling safety and improved lateral traction on constructed roads (concrete, asphalts, etc.), greater section width for support of the heavy vehicle on soft terrain, and appearance. The engineering concept behind the flotation tire can be found in its name. These tires were designed to provide flotation on loose surfaces like sand. Flotation only comes at the cost of contact pressure. Flotation is achieved by minimizing the surface pressure per square inch exhibited by the vehicle. These features are important for heavy, full size trucks and SUV’s, but not most trail vehicles.
This chart represents the recommended tire width, based on the vehicles weight (GVWR).
|Several Real World Examples: (just to show I am not the only one who believes in a narrow tire)
The Turtle Expedition who has literally traveled around the world used a 255/85 R16 (33.3 x 10) for many thousands of miles on their full size Ford. Land Rover uses narrow 7.0 R16 XCL tires in most of their Camel Trophy events. The Rain Forest Challenge and The Trophy challenge have all been won by the aggressive Simex Trekker tire (35×11.00). Tom Sheppard often uses the 7-7.5 R16 Michelin XZL and XCL for many of his expeditions. All very narrow tires in relationship to their height…
|A Brief History of Tire Design and Engineering:
The History of Flotation Tires: Tires in the past were always tall and narrow. From the 4” wide solid train wheels to the earliest automobile, tires were always tall, and very narrow. It was not until the late 1970’s that this trend began to shift, with the popularity of radial tires increasing, along with the size of American full-size trucks. These factors are what created a change from the older bias designs and sizes (Like 7.5 16, etc.). The trucks were bigger, heavier and traveled at faster road speeds, so the application of a wide tire became more appropriate.
Metric Tire History: Metric Tire engineering became standardized in 1964 with the inception of the European Tire and Rim Technical Organization (ETRTO). This consortium pursued design and fitment standards that optimized tire performance and safety in the European market. One of the first results was the creation of a standardized tire range and labeling method. The range first included the sizes of 235, 265, 285, etc. with aspect ratios of 75% of the tire width. The engineers determined that the ratio of 75% created the best compromise between handling safety on the road and low surface traction performance. As a result, metric tires for tight trucks are typically found in that aspect ratio (example= 265/75 R16).
• Durometer, Viscoelasticity (Hysteresis)- I am going to touch on this lightly in this article, but a softer durometer rubber compound will have a much higher adhesion and deformation rate than a hard tire. There are several tires available with softer compounds, like the BF Goodrich Moab edition and the Goodyear MT/R. An easy test of the viscoelasticity of tire rubber is to press your thumbnail into the tread. The longer it takes to recover, the softer the durometer and higher the hysteresis. However, the softer tire will also wear out much faster.
• Siping- Siping is a great way to improve a tires traction. Siping provides greater tread deformation to the road surface, which is why it is so effective on icy and wet roads. The more the tire can conform to that very slick surface the greater the traction.
• Tread Design- On a high traction surface like dry concrete, a totally smooth tire has the greatest traction as the adhesion rate is highest between the two surfaces. On the trail however, surfaces are varied, including wet rocks, mud, dirt, etc. That is why off-road tires are so specialized and require a compromise of other capabilities. As a general rule, and aggressive all terrain tire with soft tread compound and siping will provide the best overall performance. A Goodyear MT/R or BF Goodrich MT with siping cut after purchase will also perform well in varied terrain.
Tread Design- Selecting the tread appropriate to the terrain you are driving.
Deserts: An all terrain tread without large shoulder block to displace sand under acceleration. Use a tall tire without heavy lugs and slightly wider than for hard surfaces (use a tire in the 75% aspect ratio range). Avoid rims taller than 16″ as it is necessary to have sufficient section height to allow for a long contact patch (for flotation) when aired down. (recommended tires: BF Goodrich (BFG) All Terrain KO, Yokohama Geolander A/T+II’s)
Mountains: The mountains will present the most rugged terrain, requiring the greatest clearance, traction and damage resistance. Choose a tall, narrow tire (in the 80% aspect ratio range). One that is a load rating or more above you GVWR requirement to ensure a sufficiently strong sidewall. Rocks, loose climbs and ledges are present on many mountain tracks. Use either an aggressive all terrain or a mud terrain tire in these conditions, and favor brands with stronger sidewalls. (Recommended Tires: BFG Mud Terrain and all terrain, Goodyear MTR).
Jungles: Jungle tracks require a tall, narrow, and aggressive tire. Large voids between tread blocks allow the tire to clear mud from the tire and maintain traction. The large voids also provide lateral control to help limit sliding and oversteer. Use the tallest tire possible (without excessive suspension lift), to allow axle clearance in deep ruts. (Recommended tires: BFG Mud Terrain KM, Interco Super Swamper Radial, Simex Jungle Trekker)
Section Width- A narrow tire will provide superior performance to a wide one. Wide tires are not appropriate for use on an expedition vehicle, unless they are crossing the Gobi. Contact pressure and its affect on adhesion, deformation and mechanical keying are the critical components of traction on rugged terrain.
Section Height- As a general rule, expedition vehicle tires do not need to be very tall, unless the vehicles break over, approach and departure angles require it. Typically a tire taller than 33-34″ is not required. Do not select a tire that is so tall that it requires lowering the bump stops, or fitting the vehicle with a suspension lift of greater than 2-3 inches. Most well designed SUV’s intended for extended, rugged terrain travel have sufficient clearance from the factory, or can be fitted with a minimal lift (1-2 inches). Of course, the larger the vehicle, the larger the tires that are mounted. Unimog’s for example use nearly a 35″ tire from the factory.
These are powerful winches and fast compressors and they are convenient.
I do NOT recommend them !
The problem is: The same motor and relay operate both the winch and the compressor. If either the motor or the ralay fail you not only don’t have a winch, you don’t have a compressor either.
Winches are very seldom used and only run for short periods . If you travel with a Group it is likely will not use your winch for years. When you do, it is usually only for a couple of minutes run time.
You use your compressor just about every time you go 4 Wheeling. It also runs for a long time airing up 4 tires. Since you are using the same motor/relay as the winch you put a lot of “Miles” on them.
Another problem is, the Power Plant winch/compressor is mounted on the front of your 4×4 where it is exposed to lots of dirt. There is no way to lubricate it or to really clean it. Airing up 4 large tires takes time and the compressor gets hot causing it to fail over time. Since you use it almost every trip it gets a lot more hours on the motor & relay than a winch would get.
I’ve had my Power Plant for about 10 – 12 years and my 4 th motor just failed. I’ve also had 2 relays fail. Each time the motor repair costs more than a good portable compressor or inexpensive winch costs.
The only place to have a Warn winch repaired is at Tri-County Gear near Ontario CA. They don’t carry parts and neither does the factory. Spare parts are built to order. That means two trips to Ontario. 1 to diagnose the problem and order the parts and another to install them. It takes a day to go to Ontario, have the problem diagnosed and come home. Then another trip to have the winch repaired a week or two later when the parts arrive.
One can buy a couple of good portable compressor and 1 or 2 less expensive winches cheaper than a Warn Power Plant Compressor/Winch .
I do not recommend buying a Warn Power Plant Winch/Compressor combo.
Many people believe that using a higher Grade/Octane than called for in your User Manual is better for your engine. It is not. Using a higher octane than specified for your engine is not better for the engine and can cause damage. Too high Octane can cause Un-burned fuel to pass through the combustion chamber into your exhaust system damaging it including your catalytic converter. An exception is at high elevation. There lower octane fuel than specified for normal driving elevations is recommended . If you go to a gas station in high elevation locations like in Colorado you will notice that the octane rating for each grade (Reg./Mid/Premium) fuel is lower than the octane ratings at lower elevation location.
The purpose of being able to disconnect the front sway bar on a straight axle vehicle when off road is to allow the left and right front tires to move up and down somewhat independently. With the front sway bar connected, whenever the wheel on one side goes up the sway bar tries to also lift the other wheel. When one wheel moves up like to go over a large rock the sway bar tries to move the other wheel upward too. Likewise with sway bars disconnected, when one wheel drops, like into a hole, the sway bar tries to make the other side drop. This causes the whole vehicle to rock side to side more. With the sway bar disconnected articulation is improved because each wheel can move somewhat independently. Besides giving a much more comfortable ride off-road, having the sway bar disconnected tends to keep both front wheels on the ground and thus improves traction.
A sway bar is basically intended for highway use. In sharp turns, particularly at high speed, the sway bar tends to reduce a side to side rolling motion of the chassis particularly in turns at high speed.
Steve Harlow has written a detailed explanation of a cooling problem he recently experienced.
As long as there is ice in the water inside the ice chest, you should not drain it unless the contents are being damaged by the water. When water still has ice in it, the water is at or near 32 degrees F. If that is colder than the air outside the ice box it is continuing to cool the contents. You should not drain it unless you the contents are being damaged by the water. A good solution is to put your ice inside a “Dry Bag” like is used for kayaking to keep things dry. As the ice melts, the water will stay inside the dry bag and not damage the ice chest contents. Keep in mind that when you drain the water, its volume is replaced by warm outside air. Thus warming the ice chest contents.
High lift jacks are notorious for being Unreliable and Dangerous tools for changing tires. High Lift jacks are also heavy and bulky. They are not the best tool for lifting your vehicle for changing a tire. High Lift Jacks are also poor tools for the other things some people claim they can be used for.
Much better and safer tools for lifting vehicles are available. A safer way to lift your vehicle on the trail to change a tire is the jack that came with your vehicle. Probably Either a scissors jack, screw jack or a bottle jack. For Liability reasons, no manufacturer includes High Lift Jacks with new vehicles and they do not allow their franchised dealers to install high lift jacks as aftermarket items when they sell a new vehicle.) If your vehicle has been lifted so the OEM jack is no longer tall enough to change a tire, carry blocks to allow it to work. Or take a look at hydraulic jack extensions like the ones offered by Bogert Manufacturing at Safejacks.com
One reason high lift jacks are unreliable is that they are badly designed, crudely manufactured and are seldom maintained properly. Also, they are usually carried outside of vehicles where they are subject to weather and dirt. The mechanism for these jacks is easily jammed either from dirt, rust or mechanical scoring of the moving parts. Generally whenever you go to use your High Lift you also need to get a Hammer and Lubricant to make the mechanism work.
Another problem with them is because many people use High Lift Jacks improperly when changing a tire. Most people simply put the jack under the Bumper or Rocker Panel Slider and begin to lift the vehicle. They have to lift the vehicle quite a a bit before the tire begins to lift off the ground. The reason is that lifting from the bumper or the body one has to first “Unload” the springs before the tire begins to lift. As a result the jack has to be high up on the mast, thus less stable. This is particularly dangerous if the vehicle is not on flat and solid ground.
If you still insist on using a high lift jack, below are some techniques that make using a High Lift Jack safer.
- Make sure the wheels are chocked to prevent the vehicle from rolling.
- Try to place the foot of the jack on level, solid ground. Often this is not possible.
- Use a ratchet strap between the frame and the axle so that when you lift the frame from the bumper, the tire raises immediately, without having to first unload the springs.
- Make sure everyone stays clear from under the vehicle or near the jack.
- When lowering the vehicle do not stand too close to the jack handle.
- When lowering a vehicle on a High Lift Jack, NEVER let go of the jack handle.
The best place to store your high lift jack while on the trail is back home in your garage.
About High Lift Jack Hood Mounts:
I can’t believe anyone mounts their High Lift Jack on their hood. Do you really want that heavy mass of iron near your head in an accident, particularly a rollover? It is likely going to break loose from the sheet metal hood in an accident .
Many of our Run Leaders now Require all Participants to have a 2 Meter Ham Radio in their vehicle. No License is required to buy a Ham Radio or to monitor Ham frequencies or to transmit using Ham radios in an emergency. A good 2 Meter Hand Held is the Baofeng UV-5 R which is available on eBay or Amazon for less than $30.
We recommend all 4 Wheelers buy a Ham Radio for their 4×4.
Always run your engine when using your winch. Running your winch on the battery alone will cause the battery voltage to drop and overheat the winch motor.
When airing up your tires with a 12v compressor, always have your engine running. When the compressor is running on your battery alone the voltage will drop and your compressor will overheat, damaging the compressor motor.
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When pulling a stuck or disabled vehicle with a tow strap, avoid pulling with the towing vehicle in reverse. Pulling in reverse applies most of the load on the towing vehicle’s weaker front axle. It often results in a broken front axle U-Joint.
When convoying on the highway, all vehicles should drive with their headlights on. They also should leave enough space between vehicles so vehicles wanting to pass from the rear can have room to duck in to the line if needed when traffic approaches.
Winches usually go long periods without use. Often years.
It’s a good idea to check your winch, from time to time, before it is needed to make sure it operates .
When you need a winch, you need it to work !
Often, when one asks 4 Wheelers where their tow strap is, they will say in the back of their vehicle, often still in its original wrapper inside their tool box.
In an Emergency, when you need a tow strap, you usually need it quickly. Tow straps should be somewhere the driver can reach it while in their seat. You certainly don’t want to have to open the back and sort around trying to find the strap. When alone, a good place is on the floor in front of the passenger seat. If you have a passenger, on the floor behind the passenger seat.
Runs don’t “Just Happen”. The only reason any runs get scheduled is because some Member has taken the time to Plan, Post and Lead a run. If no one “Steps Up” there will be no Runs. Leading a Run is Fun and Easy and there is less dust.
If you’ve been a Member for some time and have never led a Run, it’s your turn! If you need ideas or suggestions about trails or if you have any questions about leading, email me at email@example.com.
See: How to post a Run Announcement.