When we’re focused on boat buying, we look critically at the boat. We scrutinize its condition and whether it will meet our needs. On the other hand we probably don’t pay as much attention to boat trailers as we should, which is interesting given the ratio of how much time the boat spends on it compared with the amount of time it spends on the water. If what you’re carrying is important — and a boat certainly counts — you should spend some timing thinking about what kind of trailer you’ll need. Like so many other products, the quality of trailers varies widely, and if you look closely in all the right places you can spot the differences. As simple as it sounds, a decent rule of thumb when trailer shopping is, “you get what you pay for.” Let’s look at the subject in terms of:
- Boat Trailer Size and Capacity
- Boat Trailer Parts And Terms
- Boat Trailer Type
- Boat Trailer Safety Features
Boat Trailer Size and Capacity
First is size. Of course, the boat determines the size of the trailer you need. Tandem-axle trailers are nice, but they have twice the number of tires that eventually need to be replaced, and I don’t know anyone who relishes buying trailer tires. So, unless your boat is at least 20 or so feet or longer, or inordinately heavy, or unless you do lots of long-distance trips with your boat, you can economize by going with a single-axle trailer. It’s cheaper to operate long-term.
However, if you do take long trips or haul a large load, a tandem-axle trailer is more stable at highway speeds. Plus if you get a flat on the freeway, having two axles offer a measure of safety you don’t get with a single-axle trailer. Dual axles also spread the load more effectively over the four-tire contact patches. And tandem-axle trailers also can be equipped with brakes on both axles, which greatly decreases stopping distance.
One more note about trailer size and capacity: more is always better. There’s nothing wrong with putting a 2,000 pound boat on a trailer with 4,000 pounds of capacity, but putting a 4,000 pound boat on a trailer with 2,000 pounds of capacity is a sure-fire disaster. You should always overestimate the load (don’t forget to include things like a full fuel tank, gear, and accessories) and be sure that the trailer’s capacity far exceeds it.
Boat Trailer Parts And Terms
Next you should learn the full terminology for the parts of a boat trailer. This will help you speak to your boatyard about proper maintenance and repairs that will inevitably needed. Boat trailers require constant maintenance, especially when they are being used often in salt water, and should be checked regularly. We have a full guide to boat trailering that summarizes how to trailer a boat properly and includes more information on the parts of a boat trailer, but below is a helpful diagram with all the key parts of a trailer that you should learn, know and understand.
Above: The anatomy of a boat trailer – key parts and terms to know. Diagram by Boat Trader.
Boat Trailer Type
Unless you know something I don’t, there are two materials from which to build a boat trailer: steel and aluminum. Obviously steel is usually stronger, but because it is a ferrous metal, it will rust. Aluminum corrodes, but it won’t rust. Raw steel is a cheaper material than aluminum, but that doesn’t mean all steel trailers are cheaper than their aluminum counterparts (though usually they are).
As a general rule, if you do all of your boating in freshwater a steel trailer works out just fine. It will rust if you leave scratches in the paint unattended, but a decent steel trailer used in lakes and rivers should last the life of your boat if you maintain it properly. Conversely, if you do your boating on the ocean or the Intracoastal Waterway, you should opt for an aluminum trailer. They’re not as pretty as a steel trailer with paint that matches your boat and tow rig, but as we mentioned earlier, they don’t rust.
There are also two different types of trailer support system: rollers and bunks. Rollers tend to make loading and offloading a bit easier, but they don’t cradle a hull like bunks do. Also, rollers do not distribute the boat’s weight the way bunks do. Boats that sit unused for a long time on roller trailers (as they often do in winter) can develop a “hook” in the running surface at the transom, or other imperfections. For the amount of money you spend buying a boat that goes fast, and on modifications to make it go faster, the last thing you need is a tweaked bottom.
Keep in mind, however, that boat companies which make their own trailers engineer them so that the rollers and/or bunks align with the stringers to provide support in places where the boat is strongest. The bottom line? If a trailer was made to match a specific boat, either system works well and rollers will make launching and retrieving easier. But if you’re not getting a trailer specifically designed for the boat, going with a bunk trailer is far less risky.
When it comes to bearings, yet again there are two types to choose from: grease bearings and oil-filled hubs. Grease bearings have been around forever and a day, and work great. Oil-filled hubs maintain an oil bath around the bearings and also work great. Some would say even better. However, they have some drawbacks. First, if the trailer sits for an extended period of time condensation can build and the top of the bearings, exposed to air, can rust. There’s a simple fix, by simply moving the trailer a foot or two every couple of months to re-oil the exposed part of the bearing. Second, the plastic caps on the sealed hubs have been known to shatter upon impact, so if something smacks the cap all the oil can leak out.
For suspensions, you guessed it, there are two types of systems to choose from. Torsion-bar systems, in which a torsion bar runs inside the axle, allow for a lower ride height. The drawback is that the system is more costly than leaf springs, and it can hide early signs of rust. Leaf springs have been used for centuries, and they are solid performers. Be sure to get a setup that can handle the weight of your boat. A lot of manufacturers put three-leaf springs on trailers, but you can find better models with five-leaf springs, which are stronger and less likely to fail over time.
While you’re crouched beneath the trailer counting leaves, also make note of the trailer’s hardware. Does it have stainless Bearing Buddy caps or chintzy stamped steel caps that will allow water into your bearings? How thick is the metal? Are the welds neat or do they look like a third-grader laid them? Quality is important.
Pay attention to the thickness of the metal used in the trailer’s main construction, including the cross-members, and compare trailer-to-trailer. A lot of manufacturers are using thin stuff simply because it’s cheaper. This logic applies to aluminum trailers, too. Not only should you look at the thickness of the aluminum, but also at the height and the width of the supports. Taller, thicker I-beams are stronger. For more information about the materials and hardware in boat trailers, see Boat Trailers 101: Materials, Brakes, Hardware.
When shopping for a trailer, you can tell a lot by paying attention to the details. One of the best ways to shop is to attend one of the larger boat shows. Look at all the trailers you can find in one day and you can notice the subtle differences and make an educated decision.
Boat Trailer Safety Features
How a trailer is set up to secure the boat is a critical feature. I towed boats for a long time without the stern being attached to the trailer, but now I insist on it, for the same reasons we wear seat belts. It’s only slightly discernible, but you really can feel the difference from behind the wheel. You hear one thump when going over bumps instead of two. The boat and trailer move as one, and if you ever get into a situation that involves a panic stop, or worse, a collision, there’s one less moving object in play. Many modern high-end trailers have ratchet straps welded to the frame, so strapping down the transom is quick and easy. There’s also a safety need for a good bow attachment point. That means a sound crank mechanism, roller, strap, and bow eye. A safety chain should also be located at the bow stop.
Brakes are another significant concern. Surge brakes are the most common, and they’re triggered when a hydraulic actuator in the trailer tongue is pressured by pushing against the tow hitch. They work well, but there can be a second or so of delay between you hitting the brakes in your vehicle and the surge brakes kicking in. Electric brakes are electronically linked to the tow vehicle’s braking system, so there’s zero delay.
You’ll also have a choice between disc or drum brakes. Disc brakes have better stopping power and fewer moving parts, and are generally considered superior. However, as one might expect, they’re also more expensive. Whenever you’re looking at a tandem-axel trailer, give bonus points if it has brakes on both sets of wheels instead of just one (which is far more common).
For general boat trailering advice and best safety practices, see:
Boat Trailering Video Series: Expert Advice
For information about boat trailer maintenance, see:
- Boat Trailer Maintenance Priorities: What to Fix First
- Boat Trailers: Maintain Your Bearings
- Bleeding Boat Trailer Brakes
For information about trailer tires, see:
Okay: get ready, get set… go boat trailer shopping!
Editor’s Note: This article was originally published in April of 2016 and was last updated in October of 2022.
0 Comentarios