By Mark Polk
RV Education 101
With their multiple slideouts, washers and dryers, large holding tank capacities, ample storage space and other amenities, it’s easy how today’s motorhomes can be overloaded. But overloaded motorhomes are extremely dangerous.
Weighing your motorhome properly can mean the difference between a safe, enjoyable trip and a costly, disastrous trip.
Let’s take a look at my Top 7 Reasons for Weighing your Motorhome. There are more than seven reasons, but my goal is to highlight some of the most important ones.
1. Safety, safety, safety: Driving an overloaded motorhome is a leading cause of RV-related accidents. Overloading your motorhome puts you, your passengers and other people in harm’s way.
2. Tough on the tires: A motorhome’s tires are the most vulnerable component affected by overloading, because the tires are not inflated properly for the load. Failure to maintain correct tire pressure can result in fast tread wear, uneven wear, poor handling, and excessive heat buildup, all of which can lead to tire failure.
Another problem is when you weigh your RV and the total weight of an axle is within the axle’s weight rating, but it may be overloaded on one side of the axle or the other. For example, let’s say you have an axle that is rated for 6,000 pounds. When we weigh the RV, the weight on that particular axle is 5,950 pounds. We are within the weight rating for the axle. But when we weigh each axle end separately we discover that one end weighs 3,400 pounds and the other end weighs 2,550 pounds. We are still within the 6,000- pound axle weight rating, but the tires are rated for 3,000 pounds at a specified psi. This means the axle end that weighs 3,400 pounds is overloading the tire by 400 pounds, even if the inflation pressure is correct. Eventually the overloaded tire will fail.
3. Suspension system and brake problems: Overloading can lead to rapid vehicle suspension system wear, or component failure that includes springs, shock absorbers, brakes and tires. Overloading the motorhome increases the stopping distance. If serious overload conditions exist for extended time periods, the brakes can fail completely.
4. There is a REASON for weight ratings: The suspension system, tires, wheels, brakes, axles and the motorhome itself all have weight ratings. Weight ratings are established by the manufacturer and are based on the weakest link in the chain. When you exceed a weight rating you are overloading one or more of the components on the RV and risk wearing the component out prematurely or complete failure of the component.
The Gross Vehicle Weight Rating (GVWR) is one of the most crucial safety factors for your RV. The GVWR is the maximum allowable weight of the vehicle when fully loaded for travel including all passengers, all cargo, fluids and fuel. The GVWR is equal to or greater than the sum of the unloaded vehicle weight (UVW) plus the net carrying capacity (NCC) for the motorhome.
The Gross Axle Weight Rating (GAWR) is the maximum allowable weight that can be loaded on each axle of the RV. The GAWR is based on the lowest weight rating of other components in the system, like suspension components, brakes, wheels, and tires.
The Gross Combined Weight Rating (GCWR) is the maximum allowable combined weight of the fully loaded motorhome and the fully loaded vehicle/trailer towed behind the motorhome. It is dangerous to exceed any weight rating, and the only way to know is to have the RV weighed.
5. Poor weight distribution: This is a common problem with RVs. When weight is not properly distributed and/or the RV is loaded improperly, the tire(s) and other components on the end of the axle that is overloaded are subject to failure. When a tire fails many RVers attribute it to a defect in the tire, but that is seldom the case.
To ensure proper weight distribution, weigh each axle end separately to determine if a tire overload condition exists. If an overload condition exists, it must be resolved immediately. In some cases it might be possible to redistribute the weight and then weigh the axle again. If the overload condition still exists you will need to remove some of the weight from the RV.
6. Untimely breakdowns and costly repairs: When an overload condition exists, components on the RV can wear out prematurely. Transmissions overheat, brakes wear out, tires fail and the result can be an unexpected and sometimes dangerous breakdown. This situation often can be avoided by knowing and managing the weights in and on your motorhome.
7. Unsafe, illegal: Overloading your motorhome is both unsafe and illegal! That’s the bottom line.
That’s some pretty convincing reasons for weighing your RV, but just how do you go about it? The actual process of weighing your RV is not that difficult. It may take a little time at the scales, but it is well worth it to know that you are traveling safely within all weight ratings.
The first step is to find certified scales where you can weigh your RV. This shouldn’t be a problem; look in the Yellow Pages under moving and storage companies, gravel pits and commercial truck stops. If you attend an FMCA convention, have your coach weighed through the RV Weight & Tire Safety Program, sponsored by FMCA and the Recreation Vehicle Safety & Education Foundation (RVSEF).
There are several different kinds of scales. It’s important is to find scales where you can weigh individual wheel positions in addition to the overall weight, and the axle weights. Remember: We said earlier it is quite possible to weigh an axle and be within the Gross Axle Weight Rating, but you can exceed the tire rating on one axle end or the other. Call the phone number where the scales are located and ask if it is possible to weigh your RV in these configurations.
The next step is to weigh everything. On the day you head to the scales, have the motorhome fully loaded for travel. If you tow a vehicle or trailer behind the motorhome, take the loaded vehicle with you. Have it loaded as if you were leaving on a camping trip. Be sure to include all passengers, cargo, food, clothing, fuel, water and propane.
Here is a link to a brochure that you can download, print and take to the scales with you. It will walk you through the proper procedures for weighing your RV: www.bridgestonetrucktires.com/us_eng/rv/index.asp
Always keep in mind that weights, over time, can change according to how you load and distribute the weight in your motorhome. Get in the practice of weighing your RV periodically to stay within all weight ratings. Whenever an overload condition exists, resolve the problem before using your motorhome.
|RV expert Mark Polk owns RV Education 101, a North Carolina-based company that produces and sells educational videos, DVDs and E-books on how to use RVs. Mark has more than 30 years of experience in RV maintenance. He retired from the U.S. Army in 1996 as a Chief Warrant Officer Three, specializing in wheeled and track vehicle fleet maintenance operations. He and his wife, Dawn, started RV Education 101 in 1999. They travel with their two boys in a 35-foot Type A motorhome.