There are few things as important and as underappreciated as the tires on horse trailers -- they can give your horse a smooth ride and make pulling a breeze when properly matched to your axles and load, or they can create a hauling nightmare that may cause you to think twice about ever getting on the road again. Choosing tires, whether it’s for existing trailers or new custom horse trailers, requires a little bit of understanding of how tires work and what those mysterious codes really mean.
Selecting the Right Tire
Before you even consider buying new tires, you need to check the Gross Vehicle Weight Rating (GVWR) of your trailer. This number tells you how many pounds of trailer, horse and load your trailer was designed to carry -- it’s not a suggestion, it’s the maximum the trailer is designed to haul. Exceeding the GVWR is a very bad idea that may result in catastrophic brake, axle or tire failure at an inconvenient time, like when you’re doing 70 on a long stretch of desert highway.
Once you know how much weight your trailer will carry, count all the tires. Most trailers will have four, but some older trailers may have only two. Take the GVWR and divide it by the number of tires on your trailer -- that’ll tell you what the weight rating for each tire needs to be. Since your load is spread out evenly over all of these tires, they should be identical to one another.
You may be asked if you want “LT” or “ST” tires for your trailer, that’s a harder question to answer, especially if you’re starting from scratch. “ST” is the designation for “special tires for trailer highway service;” “LT” is for “light truck.” Both can be used on the highway safely. Some people say that “LT” tires ride a little smoother and are more robust in case of emergencies, but LTs are rated for less weight than their identical “ST” counterparts.
The “LT” designation doesn’t have enough side wall stiffness to support a top heavy load, such as an RV or horse trailer, so it can have the tendency to “roll” when going around curves. For this reason, we recommend “ST” for trailers and not “LT.”
Unfortunately, there are plenty of horse owners who believe they can safely overload their trailer if they install tires rated for greater weights, or to put it another way -- they’ll put the tires used on horse trailers with living quarters on a two horse trailer. This is a really terrible idea. Even if their trailer’s axles and brakes don’t come apart because of the excess load, the ride is going to be horrific for horses and people alike. This is why it’s always better to choose tires rated for your trailer’s GVWR or slightly below.
Taking Care of Your Tires
You decided your new two horse trailer would do just fine with four LT tires under it, but that’s not the end of your tire education. At the end of the day, a tire is a fancy rubber tube under an incredible amount of pressure -- that means that even the smallest failure could go catastrophic in no time. Maintenance is vital to the life of your horse trailer tires. Luckily, most of what they need is easy. Before you take your trailer out, run through this tire checklist:
How’s the Tread? Always check the tread on your tires before you go anywhere -- the tread helps your trailer grip the pavement and acts as a shield to protect the belts from significant road damage. Any time you have less than 1/16 inch of tread left, you need new tires. Check the depth of the tread in several spots to ensure that your tires are wearing evenly.
Are There Visible Problems? Cracks, bald spots and areas where the belt shows through the rubber aren’t small problems that can be ignored. In fact, they’re tire failure waiting to happen. Look for these obvious problems, as well as less obvious problems like construction debris stuck in your tire’s tread that could puncture the tire during travel.
What’s the PSI? A common cause for blow-outs is under-inflated tires, so check the pressure before and after outings, each and every time. On average, your tires lose 1 to 3 PSI each month, even in storage -- expect to have to inflate your tires to their recommended level before each trip.
You can ensure that you always know exactly how well inflated each of your trailer tires is by installing a tire pressure monitoring system. Sensors on the valve stems wirelessly transmit information about the inflation level of each tire to a monitoring system on your dash -- you can even set an alarm to alert you to significant drops in pressure. They will work on nearly any size trailer tire and can be instrumental in preventing blow-outs during trips.
Trailer tires are considered spent after five years, no matter what, but many must be replaced after just three. You should be checking your tires yearly for signs they’re wearing out, especially inadequate tread. Trailers that don’t go much might seem immune to the need for frequent tire replacement, but they’re the ones that need it worst -- especially if they’re stored with the tires touching the ground between trips. Ground storage is the best way to destroy a new set of tires on a trailer. When you put your trailer away, make sure to remove the tires and store the trailer on blocks. The tires should be stashed somewhere cool and dry, like an insulated garage, to protect them from the elements.
When you’re ready to build your next custom horse trailer, with your choice of options and your favorite tires, let Double D Trailers handle it. We’ve got the expertise to put together a horse trailer that’s perfect for you and your horse and we’ll explain what we’re doing every step of the way. Whether you’ve got questions about tires or trimwork, we’re here to help you design a horse trailer that will fit your needs today and well into the future. Check out our website or give us a call at 1-888-244-2029 to get started on your custom trailer.