Wecome To RVs and OHVs

This blog is all about RVs (recreational vehicles) and OHVs (Off Highway Vehicles), camping, and survival
and how they work together to provide wholesome family fun and great learning opportunities.
Many posts are intended to familiarize novice campers and RVers with RV systems and basic camping and survival
skills. But even experienced RVers and campers will enjoy the anecdotes and may even benefit from a new
perspective. Comments, questions, and suggestions are encouraged.

Search This Blog

Loading...

Thursday, May 21, 2015

Hydration

Maintaining adequate hydration while camping and involved in related activities, such has hiking, OHV riding, and horeseback riding, is essential to both comfort and good health.  Because of lot of our camping and related activities take place in warm or even hot weather, our hydration requirements are usually greater than normal.  The effects of dehydration can range from discomfort to coma to death!

When you begin to feel thirsty, you are already starting to get dehydrated.  To avoid dehydration start by pre-hydrating your body prior to your activities.  When dirt biking we start drinking plenty of water and sports drinks the night before our planned rides.  While having enough water is the biggest concern, you will also need to maintain a proper balance of electrolytes to ensure comfort, performance, and good health.  One of the most important electrolytes is salt and it is one of the first to get depleted through perspiration.  You can buy salt tablets that are convenient to carry during activities.  How much salt do you need?  That will depend on several factors, including your body size, outside temperature, and level of activity.  You might be able to find some guidelines via online research, but it may be best to check with our doctor so you get enough but don't over do it.

If you find yourself feeling lethargic during hot weather, you are probably suffering from dehydration.  Drinking plenty of water will probably restore your energy levels.  By the way, it is best to drink small amounts frequently rather than gulp down a whole bunch at once.


Drink small amounts of fluids frequently, especially during very hot weather and/or strenuous activity.  Don't wait until you feel thirsty and then chug-a-lug a whole lot of liquids.  Maintaining your fluid levels by small drinks throughout the day works much better and you will be far more comfortable. You REALLY don't want to chug down a quart of cold water and then do something physically demanding, like riding a dirt bike or a horse!  That is a good way to feel really sick to your stomach really quickly.

A frequent and painful symptom of dehydration is heat cramps.  These usually occur in the arms and legs but can affect just about any muscle, like those in your throat or even your tongue.  They are like really bad charlie horses.  For immediate relief try stretching the offending muscle.  Sometimes you may get cramps in both the front and back of your arms or legs and then it is impossible to stretch out one without aggravating the cramping in the other.  When that happens, about all you can do is find the most neutral position and have someone bring you some electrolytes to drink.  We've found that dill pickle juice works very well, especially if you hold some under your tongue so it can be directly absorbed into your bloodstream.  To avoid heat cramps altogether, drink plenty of water and sports drinks throughout the day to maintain your fluid and electrolyte levels.

Symptoms of more severe dehydration will include hot dry skin (when you stop perspiring you are dangerously dehydrated and your body can't cool itself).  You may become nauseous, dizzy, and get headaches.  If you or any of your companions exhibit these symptoms, you need to cool them down and get some fluids into them as quickly as possible.  Severe dehydration can lead to unconsciousness, coma, and, eventually, even death.  Douse a severely dehydrated person with cool water and encourage them to sip water.  An unconscious victim will require intravenous liquids so seek medical attention as soon as possible.

There are several convenient ways to carry water with you during your activities so you can drink as much as you need throughout the day.  Bottled water comes in handy sizes and a lot of backpacks and fanny packs have special outside compartments to keep them easily accessible.  There are also carriers designed specifically to hold bottled water that can be worn slung over a shoulder or around your neck if you're not wearing a fanny pack or back pack.  Some are even made of neoprene to insulate the bottle to keep the water cooler.  Here are some examples available from Amazon.com.

Canteens have been used for many years by campers, hikers, scouts,soldiers, and cowboys to carry water.   The come in various sizes, shapes, durability, and ways to be carried.  Here is a typical boy scout canteen, with a carrying strap to sling it around your neck and/or over your shoulder:
                                                   

                                                       








                                                  Image result for boy scout canteen    

Here is an army style canteen that is carried on your belt:





                                                        Image result for army canteen 

Blanket style canteens are often used when horseback riding.  They come in various sizes ranging from less than a quart to a gallon or more.  The blanket covering can be wet so that evaporation helps cool the contents.

                                                     Image result for blanket canteen 

My favorite water system for outdoor recreational activities like dirt biking is the Camelbak Hydration pack.  These are soft back packs with a vinyl bladder inside and a tube from which you can suck water directly through a "bite valve" that keeps it from leaking out between drinks.  I add a Velcro tab to the bite valve and a mating tab on the center of my chest protector so keep the tube handy for use while riding.  Here is an example of a Camelbak hydration pack:

                                                    camelbak 60282 hydration pack,50 oz./1.5l,black 



What hydration system you use will depend on the kind of activities you will be participating in and the budget you have for acquiring a system.  Small canteens are relatively inexpensive; large hydration packs will cost several times as much but will carry more water more conveniently.  The most important thing is that you make sure you always have an adequate supply of water.

You can fill your canteens or hydration packs with water or with sports drinks.  However, if you fill them with sports drinks you will have to make sure you clean them out regularly to avoid spoilage or sticky deposits.   In many, many years of dirt biking in the Mojave Desert I have found water to be the best source of hydration on the trail.  Then I consume some sports drinks when I return to camp to balance my electrolytes.  Water is far more refreshing and avoids the sticky aftertaste that often accompanies sports drinks.  I definitely do not recommend filling canteens or hydration packs with sodas!  First of all, sodas are not ideal sources of hydration, especially if they contain caffeine.  Secondly, the bouncing of the container will make the soda fizz, possibly leaking out and quickly losing all the carbonation so it goes flat.  If you're out on the trail for any time, the contents of your hydration container is going to get warm and warm, flat soda is disgusting and not something you will likely drink very much of.  Water is the best thing to fill your hydration system with.

Drink up!

Wednesday, May 6, 2015

Gas versus Diesel

Gas versus diesel powered motorhomes and tow vehicles.  The question always comes up.  And, unfortunately, there is no easy answer.  But there are some distinct advantages and disadvantages to each the potential buyer should be aware of.

Gasoline powered vehicles are generally less expensive than diesel.  They are usually less expensive to maintain also.  But they generally get poorer fuel economy and don't have the high torque of diesel engines.  If you have gasoline powered motorsports toys you can use your spare gas in your vehicle if you run low.  I've even burned pre-mix 2-stroke fuel in my truck in a pinch.  Gasoline powered chassis usually have the engine up front between the driver and passengers seats.  For some people the engine noise and heat can be a problem.  You can buy fuel for gasoline vehicles at any gas station, although you sometimes have to look for one with adequate lateral and overhead clearance to accommodate an RV.  Surprisingly enough, many motorhomes run on regular unleaded gasoline but some require more expensive premium fuel.  Be sure to know what your vehicle requires.  If you use a low or mid grade fuel and the engine starts to
"ping", upgrade to premium fuel soon, before engine damage can occur.  One cause of pinging is pre-ignition, which means the fuel mixture ignites before the spark plug fires.  This can burn valves, which leads to per performance and reduced mileage and are expensive to repair.  Gasoline powered vehicles will be subject to annual emissions inspections when the vehicle is registered where such inspections are required.  An engine also creates high levels of pollution (NOX and unburned hydrocarbons) that are really bad for air quality.

Diesel engines are more expensive but the usually deliver better fuel economy, higher torque, and longer life than gasoline engines.  However, the increased price means it may take a lot of driving to recoup the additional cost in fuel savings or longevity.  If you plan to full time and/or put a lot of miles on your vehicle, a diesel may be advantageous.  At one time diesel fuel was cheaper than gasoline, and that coupled with better fuel economy, reduced fuel costs.  But these days diesel tends to higher than premium gasoline (at least where I live).  If you do a lot of boondocking for OHV activities, you may have to carry some extra diesel fuel since the gasoline for your toys is not compatible with diesel engines.  Diesel engines in general are a bit noisier than gasoline engines, not necessarily in the exhaust system, but from direct sounds generated within the engine.  They do not have spark plugs to ignite the fuel.  The fuel is ignited by heat generated from compression.  This can sometimes be heard as a sort of knocking sound.  Diesel chassis often have the engine in the rear (known as a "diesel pusher").  On large motorhomes this puts the engine up to 40 feet behind the driver, greatly masking any engine noise.  Finding diesel fuel on the road used to mean looking for truck stops, but the proliferation of gasoline powered automobiles has made diesel much more available.  Yet even today, not all gas stations carry diesel, so you need to check the signs before you pull in.  Make sure you use only the designated diesel pump.  Putting gasoline into your diesel vehicle will cause a lot of problems and can be expensive to remedy.  Motorhomes with diesel engines may have diesel or propane powered generators.  If your camping style is such that you use a lot or propane, you may want to make sure the generator is diesel powered.  In some areas subject to emissions inspections, diesel powered vehicles are exempt from emissions inspections.  They may still be required to pass any safety inspections.  Diesel powered vehicles often have higher weight carrying and towing capacities than their gasoline counterparts. So if having a really big motorhome or being able to tow a really large trailer is important to you, you may want to seriously consider getting a diesel.

I have owned both gasoline and diesel powered motorhomes and found both to be satisfactory.  I've never full timed or taken long cross-country trips, so I was never able to take advantage of the higher fuel economy attributed to diesel vehicles.  My diesel was a 40' pusher, and, due to its size and weight, did not get deliver particularly good mpg numbers.  Unfortunately, I also saw diesel fuel climb from cheaper than unleaded regular to more expensive than premium gasoline which quickly negated the cost savings I anticipated when I bought it.

Choose the right fuel.

Sunday, April 26, 2015

The Venerable GM 454 Engine

Many gasoline powered motorhomes are fitted with a Chevrolet 454 "big block" V-8 engine.  You will find them on many older Class A's based on the Chevrolet P-30 chassis and on the modern Workhorse Chassis.  They are generally quite powerful and reliable, but not particularly stingy when it comes to fuel economy.  I've owned several 454 powered Class As, ranging from 28' to 35' and they all pretty much got about 6 mpg -- up hill, down hill, head wind, tail wind, towing a trailer, driving solo.

Over the years the 454s have developed a reputation for a few specific issues you may want to watch for if your RV is thus equipped.  For starters, they tend to generate a lot of heat.  The typical solution is to improve the exhaust system, replacing the stock manifolds with headers, enlarging the exhaust pipes, and installing free flow mufflers.  I've seen the stock manifolds on more than one motorhome glowing cherry red after climbing a steep hill.  That kind of heating contributes to warped manifolds causing noisy nd dangerous exhaust leaks.  Upgrading the exhaust system will have other benefits beyond getting rid of heat.  A more open exhaust reduces back pressure and lets the engine "breath" better.  I experienced a very dramatic demonstration of the affects of a restricted exhaust system when I blew out the "donut" gasket between the header and the exhaust down pipe on one of my 454s.  I was climbing a gentle hill at the time and the motorhome jumped forward like it had been kicked in the butt when that gasket blew out.  A better exhaust is one of the key features of the famous "Banks Powerpack".  Another major component of the Banks upgrade is an improved air input system.  Together these two changes typically deliver both improved performance and better gas mileage.

That heat also translates into well known starter problems.  The starter is necessarily trucked in right under the right manifold where it is exposed to very high temperatures.  The most common symptom is hard starting when the engine is hot.  The starter binds up inside and can't overcome the internal resistance with enough force to turn the engine over.  Over time, the problem further damages the starter so it doesn't work well anytime.

There is another problem that is often mistaken for a starter problem.  The symptoms are much the same.  The starter will turn over once or twice and then stall.  This is often due to a faulty ground strap between the engine and the vehicle frame instead of a dead  battery or worn out starter.  Over time the connection between the ground strap terminal and the frame can become rusted or corroded so it doesn't make a good connection.  If you experience starting problems that would be one of the first things to check.  Many times it can be corrected simply by cleaning the terminal and the spot where it attaches to the frame.  Or you may want to replace the entire ground strap, especially if it is small or flimsy to start with.  And old fashioned braided steel battery ground strap about an inch wide is a good choice if you have to upgrade.  I've even heard of at least one RVer who added a second ground strap on the right side of the engine.  Perhaps he has a "Valley Girl" mentality ("For sure, for sure.").  A second strap shouldn't be necessary, but it certainly won't hurt.

You may find folks who recommend an oversize oil filter to increase oil capacity.  They will often claim it will even help dissipate engine heat, especially if the filter is equipped with cooling fins.  I tried the oversize filters on a couple of my rigs and can't say that I notice any perceptible difference.  However, having nearly an extra quart of oil in the system certainly won't hurt anything (except a small pain in your wallet for an extra quart at each oil change).  The extra filter area may also be more efficient at removing contaminates.  It could dilute contamination and prevent unnecessary wear.   The impact of these factors is difficult to measure.  The oversize oil filter is usually available as a direct replacement for the regular spin-on filter, but will be a lot longer.   The concensus I found in my most recent research is that over sized oil filters probably aren't worth the extra cost, but if it gives you peace of mind, it certainly won't hurt anything.

On the subject of filters, there is another filter worth thinking about:  the air filter.  First of all, you always want to keep your air filter clean.  A clogged air filter will significantly reduce mileage and performance.  I like to use a K&N resusable air filter.  They generally allow greater air flow than standard paper elements and can be cleaned and reused over and over. They are a bit pricey to buy, but since they don't have to be replaced frequently, they pay for themselves over a few change intervals.

Most 454s are equipped with fan clutches that engage and disengage the fan depending on the temperature.  You can usually hear when the fan kicks in or off  from inside the coach.  The sound can be quite dramatic.  Many drivers mistake it for downshifting when the fan kicks in.  If the fan if always engaged, the clutch may be faulty.  The purpose of the clutch is to engage the fan when it is needed for cooling.  If it is on when it isn't need, it puts some additional drag on the engine, which could have a slight affect on fuel economy, and it may prevent the engine from reaching proper operating temperature by over cooling the radiator.

Speaking of radiators, I've seen some motorhomes equipped with what I would consider to be undersized radiators.  I'm not talking about the square inches of surface or height and width, I'm talking about the number of rows of cores inside.  The more rows, the better it will cool.  If you have consistent overheating problems you should have the radiator checked.  First of all, there can be internal deposits that restrict flow and significantly reduce cooling capacity.  Secondly, you might have a radiator with only a few rows of tubes in the core.  If boiling out the radiator to get rid of deposits doesn't solve your problem, check with your radiator shop about upgrading to a heavier duty radiator with more core tubes.  Unless the extra thickness pushes the radiator back into the fan or interferes with something out front, a heavier duty radiator should bolt right in where the original was without any modifications required.  Of course the heavy duty radiator will be more expensive than an OEM replacement, but it might be worth it.

Big blocks rock!

Monday, April 13, 2015

Shake Down Cruise

Shake down cruises probably apply mostly to RVs, but even tent campers can benefit from them, especially when you are just starting out or have purchased new equipment you need to try out.  The purpose of shake down cruise is to try out all systems and equipment and see if there are any problems that need to be addressed.

A shakedown cruise should be fairly close to home, in case you find any major issues you need to deal with.  If you need to test a motorhome or tow vehicle you'll want to make the trip long enough to properly exercise the mechanical components and capabilities but you probably shouldn't take off on a major trip (inter-state or cross-country) until you're sure you have the bugs out.  Sometimes you can check out a lot of things by "camping" right at home, although you will need to do some driving to prove vehicle systems.

Hopefully weather will allow you opportunities to check out both heating and air conditioning systems in your RV an/or other vehicle.  We found a recent shakedown cruise in April was ideal.  Days were warm enough to test the A/C and nights cool enough to use the furnace.  Be sure to exercise all the major systems and watch for any signs of failure or poor performance.  Plumbing leaks on RVs, even new ones, are fairly common.  Look for wet spots or drips beneath your RV or on the walls or floor.  If the 12-volt water pump cycles when you don't have an fixture in use you probably have a leak in a pipe or connection that you should to track down before your next trip.  Until then, turn the pump off when you are not actively using water to minimize water damage until you can fix the leak.

If your RV refrigerator uses more than one power source (gas, 120 volts, 12 volts) be sure to try all the options.  Electrical connections can corrode or vibrate loose and insects may build nests in the propane gas lines.

Tent camping shakedowns can be done in your own back yard unless you need to test out your vehicle.  It is especially helpful to learn how to setup a new tent before you have to do it under the stress of doing it in camp and in front of other campers.  Checkout your camp store and lanterns.  Test your sleeping bags and sleeping pads so you can make adjustments before you are totally dependent on them.  I once discovered my 10° bag was useless even at 40° because it had been too tightly rolled in storage for too long and had lost virtually all of its insulating properties.  In most places all there was were two thin pieces of nylon cloth.  Unfortunately that happened on an actual outing and I had to make do.  Had I taken the time the check things out beforehand, I would have been able to replace the bag or at least bring along some extra blankets.

Make a list of any findings.   Your list might include provisions you need to restock as well as any required repairs and desired updates.

Shake it up (er, uh, down) baby!

Saturday, March 28, 2015

Trailer Brakes

Trailers over a certain size/weight must have brakes.  Virtually all travel trailers are heavy enough that they are required to have brakes.  Some small utility trailers and motorcycle trailers don't have or need them legally, but it is always a good idea to have them.  Tow dollies may also be equipped with brakes.  There are basically two kinds of trailer brakes:  electric brakes and surge brakes.

Electric trailer brakes are controlled by a brake controller in the tow vehicle.  The controller is connected to the brake switch so it is activated when the vehicle brakes are applied.  The controller contains a device that measures momentum.  The harder and faster the vehicle decelerates when the brakes are applied, the stronger the application of the trailer brakes.  Controllers typically have adjustments to allow the driver to increase or decrease the sensitivity of the controller to tune the trailer braking.  They also have a control to manually apply the trailer brakes.  The brakes on the trailer are activated by a magnet controlled by the amount of power transmitted from the controller.  The magnet grips the inside face of the brake drum and an attached lever push the shoes out against the drum to slow or stop the trailer.  Most larger trailers have electric brakes.  One advantage to electric trailer brakes is that the sensitivity can be tuned by the driver so the trailer brakes just right, not too much and not too little. 

Surge brakes are self contained on the trailer.   Surge brakes are hydraulic brakes.  The master cylinder is included in the surge brake activator on the trailer tongue.  The activator is designed to apply hydraulic pressure to the braking system when it senses the tow vehicle is slowing down.  What happens is there is some flexibility in the way the activator is mounted on the tongue so that when the vehicle slows down and the trailer pushes forward against the hitch, pressure is applied through the master cylinder to the brakes to slow the trailer.  The main advantage to surge brakes is that they don't need a controller in the tow vehicle.  The main disadvantage is that the driver cannot manually apply the trailer brakes.

Trailer brakes have an emergency disconnect that applies the brakes automatically if the trailer gets disconnected from the tow vehicle.   Normally, electric brake systems use the trailer battery to power the brakes if the disconnect switch is activated.  The disconnect typically consists of a pin connected to the tow vehicle so that it is pulled out of the switch if the tow vehicle is separated from the trailer.  The pin normally holds the switch open so it closes when the pin is removed, activating the trailer brakes.  On surge brakes, a cable attached to the vehicle typically pulls on a lever on the activator on the trailer tongue if the two become separated and the lever applies the brakes.  Emergency braking helps to  control the trailer if it gets disconnected from the vehicle.  Of course the first line of defense are the safety chains that should keep the two fairly close together and keep the trailer from wandering off by itself.

Properly adjusted trailer brake systems will apply braking proportional to the tow vehicle braking so both units slow down at the same rate.

If trailer brakes are too tight or too sensitive, the tow vehicle driver should feel the trailer holding the vehicle back when the brakes are applied.

If trailer brakes are too loose or not sensitive enough, the vehicle driver should feel the trailer continue to push the vehicle when the brakes are applied.

Trailer brakes are adjusted about the same way drum brakes are adjusted on any vehicle.  There is a star wheel between the bottom ends of the brake shoes which is turned to push the shoes out against the drum.  Once the shoes are pushed out enough to keep the wheel from being turned, the star wheel is backed of just enough to let the wheel turn freely.  In my experience I can usually still hear the brake shoes lightly brushing the drum.  If the brakes are adjusted too tight they will drag and overheat.  This diminishes brake performance and life and can get hot enough to cause a fire.  It will also accelerate tire wear.  If the brakes are adjusted too loose, they won't work effectively to slow or stop the trailer when needed.  If you aren't sure you can adjust the brakes correctly, have it done by a mechanic who knows what he is doing.

Controller sensitivity on electric brakes is adjusted by a switch on the controller.  It may be a rotating knob or a sliding switch.  Increasing sensitivity makes the trailer brakes come on faster and stronger; decreasing sensitivity makes them respond slower and weaker.  If the trailer seems to be tugging on the tow vehicle when you apply the brakes, the controller is too sensitive.  If the trailer doesn't seem to slow down when you apply the brakes or you can feel it pushing on the tow vehicle, is isn't sensitive enough.  Adjusting sensitivity is largely a trial and error situation.  Ideally you want the trailer braking to match the tow vehicle braking so the two slow down and stop together.

Trailer brakes are inspected by removing the drum and examining and/or measuring the amount of lining on the shoes.  Linings that are thin, cracked, or badly glazed should be replaced.  To remove the drum you will have to remove the axle nut and outside wheel bearing.  The axle nut is a castle nut that is prevented from spinning loose by a cotter pin through the gaps in the outside of the nut and the axle.  Always discard the used cotter pin and replaced it with a new one.  While you have the drum off, inspect the wheel bearings.   If they show signs of rust or wear, replace them.  Repack the wheel bearings before reinstalling the drum.  The outer bearing can be repacked by placing a glob of grease in one hand, then holding the bearing in the other hand and pressing the outer (larger end) edge of the bearing into the grease repeatedly until the grease squished out the small end of the bear between the rollers.  Repacking the inner bearing can be done in the same way if you can safely remove it.  The inner bearing is held in place by a grease seal that will have to be replaced it you remove it to extract the bearing.  The axle nut must be properly tightened when reinstalling the drum.  Your owners manual may give you instructions or torque specifications which you should follow.  If you don't have a manual or specifications, snug the nut up until the bearing retainer is tight against the bearing, making sure it doesn't cause the bearing to bind when the wheel is spun.  Then back it off about one or two gaps in the castle nut to install the cotter pin.  If the axle nut is too loose, the wheel will wobble, most likely destroying the bearings, the hub, and the drum.  If it too tight, the bearings will be overstressed and will run hot, thinning out and loosing the grease and burning up.  Here again, if you aren't comfortable with your ability to make the right adjustment, have it done by a qualified mechanic.

Any fairly good do it yourself back yard mechanic should be able to service trailer brakes.  It is pretty much the same as servicing drum brakes on a car.  There are some special brake tools that make the job much easier but it is possible to do it with ordinary hand tools.  In particular, brake pliers are designed to reattach brake springs and while it is possible to remove the clips and springs holding the shoes onto the backing plate using pliers, it is much easier with a tool specially designed for the task.  It has a screwdriver type handle and a dime-sized cone in place of the blade.  The cone fits over the clips on the retaining springs, allowing you to compress the springs and then remove the clip with a turn of the handle.  Another good tool is brake adjusting tool.  I've seen brakes adjusted using a flat screwdriver, but the size and angles of  a brake adjusting tool make it much easier and faster.  Remember, almost any task can almost be fun with the right tools and even the simplest tasks can be a pain in various body parts with the wrong tools.

Stop right!

Thursday, March 26, 2015

OHV Tires

OHVs often require special tires,depending on the terrain and riding style.  A common type of tire is an "all terrain" tire, designed to provide pretty good handling and service on most types of terrain the vehicle is designed for.  However, there are specialty tires for special conditions.  One of the most noticeable are the "paddle" tires used on dirt bikes, ATVs, and dune buggies that are driven mostly in sand --like on  the beach or in the dunes.  These tires provide a lot better grip in sand than ordinary knobbies.  But you wouldn't want to use them for trail riding.  Riding on hard surfaces will cause premature wear and the paddle design won't provide proper traction for safe operation.

OHV tires come in various hardnesses or grades of the rubber.  Which hardness or grade you need will depend on several factors such as the terrain where they'll be used and the weight and riding style of the operator.  Harder tires will last longer but may not have as much grip as softer tires.  There is no easy formula I know of for determining which tires you need.  Finding the right tire for you and your ride is mostly done by trial and error.  You might talk with your fellow riders who ride the same trails you do and see what they use and then use that as a starting point.  If you don't like the way your ride feels with a particular tire, try something else.  A tire that is too soft will wear out quickly and may give your ride kind of a squishy feeling on the trail.  Tires that are too hard may make the whole ride feel stiff and maybe even a bit squirrely.

OHV tire pressures are often very subjective.  As with any tire, don't exceed the maximum pressure on the sidewall.  My dirt bike riding friends and I typically use a "squeeze test" on our dirt bike tires.  Grip the tire between the thumb and fingers and squeeze hard.  I like it when there is just a little give so that my tires aren't too hard nor too soft, but right in the "Golidlocks" zone.  On the other hand, we were meticulous about setting the tire pressure to factory specs on the ATVs and side-by-sides we rented out when I worked as a mechanic at an ATV resort.  If you feel your ride is too hard or you feel every little pebble in the trail or road, you may be running your tire pressure too high and might want to try backing it down a little at a time.  OHV tires don't need to be rock hard.

Keep rollin, rollin,rollin.

RV Tires

RV tires, in general, tend to time out long before they wear out.  Unless you're on the road constantly, like rock band or something, you RV is probably going to spend more time sitting than it does rolling.  I've often seen RV tires with side-wall cracks bigger than the grooves in the tread, even though the tread was still well within acceptable safety limits.

Speaking of tread wear, an easy way to determine if the tread on you tires is getting too low, is to stick a penny into one of the grooves in the tread with the top of Lincoln's head pressed down into the groove.  If you can see he top of Lincoln's head, your tire needs to be replaced.

Sunlight and ozone are two factors that are very hard on tires.   Simply putting tire covers on your RV can significantly extend the life of your tires.  Keeping your RV in covered storage also helps a bunch.  I've heard that parking it under high voltage power lines can speed tire deterioration because of an increase in ozone generated by the power lines.  Properly cleaning and treating tires will also help prevent premature degradation.  Side-wall cracking is the result of the rubber drying out.  Clean, properly protected tires won't dry out as fast and some tire treatments may actually help replenish lost chemicals that protect the rubber.  I had one tire guy suggest using brake fluid to protect tires, but I'm afraid it would attract dust and dirt.  Commercial "tire shine" products should contain UV blockers and other substances that protect the tires without leaving a sticky residue.  I sometimes use the same SC-1 detailing spray I use on my dirt bikes on my tires to give them a nice shine and layer of protection.

When your RV is in extended storage the tires should be insulated from the ground.  Park on wood planks or plastic leveling blocks.  Parking on gravel or concrete is better than parking on bare dirt, but it is even better to put something between the rubber and the road.  Some folks recommend even jacking up the vehicle and taking the load off the tires.  That certainly won't hurt the tires, but it is a lot of work and, if not done properly, could create an unstable and unsafe condition.

Improper inflation and poor wheel alignment are two of the worst things you can do for you tires.  Under inflated tires will wear on the edges and run hot, wearing out faster and significantly increasing the chance of a blowout.  Over inflated tires will wear in the middle and will reduce traction, often making the vehicle steering "skittish" to the point of being unsafe.  A vehicle with over inflated tires will be much more susceptible to wind and to the "blow by" from passing trucks.  Proper tire inflation will also help maximize fuel economy.

Really proper tire inflation is more than just inflating tires to the max pressure indicated on the sidewall.  The right way to set inflation is to weigh each corner of your RV with it fully loaded the way you use it, then look up the correct inflation in inflation tables based on the weight on each tire.  If you aren't able to use this method, check the owner's manual or the ID sticker for the manufacturer's recommended tire pressure.  If you don't have an owner's manual or ID sticker, use the pressure indicated on the sidewall as a starting point.  The pressure on the sidewall is the MAXIMUM recommended pressure.  Exceeding that pressure, even if the tire looks low, is risking a blow-out.  Sometimes inflating to the maximum sidewall pressure will over inflate the tires for the load.

Keep rollin, rollin, rollin!