What's Actually Back There?
The Gross Combined Vehicle Weight Rating (GCVWR), which is determined by the tow vehicle manufacturer, is the maximum combined weight of the tow vehicle and trailer that can be hooked up and pulled safely. This means you must know the weight of the entire hauling "package": vehicle, trailer and contents.
Chances are good that the combined weight is much more than you might think.
Neva Scheve, author of The Complete Guide to Buying, Maintaining and Servicing a Horse Trailer, notes that the weight listed on your trailer's certificate of origin is usually calculated before optional equipment is added. Floor mats, spare tire and extra modifications can add hundreds of pounds more. The only way to be really sure of your trailer's base weight is to weigh it on a truck scale.
Then you must add the weight of your tow vehicle, passengers, fuel, horses, gear, feed and any miscellany. A bale of grass hay can be 50 pounds, alfalfa more. Saddles vary considerably in weight, but it would not be uncommon for a stock saddle, blanket, bridle and breastplate to run another 50 pounds; double that if you are bringing a friend's gear along. Then there is probably a tack box of some sort. If you are hauling a water tank as well, remember that each gallon of water weighs a bit more than 8 pounds. If you are camping, add corral panels and coolers filled with ice.
Altogether, you can easily add the equivalent of a fat pony to the load you thought you had and actually be at or above your tow rating.
An even greater margin of safety is prudent in some parts of the country. Joe Robertson, of Scott Murdock Trailer Sales in Loveland, Colorado-a state with highway mountain passes that can top 10,000 feet, with 5,000-foot drops coming and going-notes that "getting it going [up the mountain] isn't the issue as much as coming down the other side." He prefers working with a tow rating that is 30%-40% higher than the maximum weight you expect to pull.
Both Scheve and Robertson recommend at least a half-ton pickup to pull a two-horse tagalong trailer, with at least a three-quarter-ton pickup with a gooseneck hitch if pulling four horses or more. In a gooseneck, or "fifth-wheel" hitch, a significant amount of the combined weight is distributed throughout the body of the truck, giving greater stability and enabling the entire combination to handle more as one unit.
Tom Svejcar, of Colorado Horse Trailers in Longmont, Colorado, is an advocate for Brenderup Trailers. Developed in Europe, where the ubiquitous American pickup is rarely seen, Brenderup trailers rely on balance, a low center of gravity, and a specialized braking system to produce one and two-horse trailers that can be hauled by smaller vehicles. Brenderup's tow vehicle requirements include an engine that develops a minimum of 120 horsepower, a wheelbase of at least 93 inches, and a caution to never exceed the vehicle maker's recommended tongue weight.
Chain Reaction: Tires, Tongue, Brakes & Hitch
This brings up an issue frequently overlooked: Never exceed the capacity of the "weakest link" in the vehicle-, hitch-, brake-, trailer-, tire-combination.
"Tongue weight" is the amount of the trailer's weight that presses down on the trailer hitch. According to NHTSA tow guidelines, too little tongue weight can cause the trailer to sway. Too much tongue weight can cause insufficient weight on the front wheels of the tow vehicle, resulting in poor steering. The shorter your wheelbase, the more important a weight-distributing hitch can be to distribute the tongue weight among all tow vehicle and trailer axles.
Brake types vary. Brenderup's Inertia™ four-wheel brakes operate as the driver lets up on the accelerator, but before the brake pedal is applied. Electronic brakes have a controlling device in the tow vehicle. Surge brakes are independent, hydraulic-activated with a master cylinder at the junction of the hitch and trailer tongue. Which type is appropriate for your situation will depend on your trailer and tow vehicle's manufacturer recommendations for the weight you will be hauling.
NHTSA further recommends that all trailer tires be of the proper size, type and load-range found on your trailer's certification label. They should also be properly pressurized and of the same type, size and construction. Do not mix bias-belted and radial tires.
As with so much in horsemanship, safety and balance are two sides of the same coin when it comes to horse tow vehicles and trailers. making sure your combined unit is balanced and adequate to haul your precious cargo requires developing a serious margin of safety that will not only get you and your horses up the hill, but down the other side safely.
