8.5x14 Double Axle Diamond Cargo Trailers: The Ultimate Buying Guide

Introduction: Why the 8.5×14 Double Axle Diamond Cargo Trailer?

Choosing the right enclosed cargo trailer is a significant investment. For businesses, contractors, and serious hobbyists, the decision often comes down to finding a perfect balance of size, capacity, and durability. The 8.5×14 double axle enclosed cargo trailer from Diamond Cargo consistently emerges as a top contender, offering a versatile platform for a wide range of hauling needs. This guide will provide a comprehensive overview of this popular model, empowering you to make an informed and confident purchase.

The Sweet Spot: Size, Capacity, and Versatility

The 8.5×14 dimensions hit a sweet spot for hauling. The 8.5-foot width provides ample interior space for wider items like UTVs, small vehicles, or large equipment, while the 14-foot length offers substantial volume without becoming overly cumbersome to maneuver. Paired with a double axle configuration, this trailer can handle significant weight, making it an ideal choice for landscapers, construction crews, mobile workshops, and motorsport enthusiasts.

Introducing Diamond Cargo Trailers: Quality and Reputation

Diamond Cargo has built a strong reputation for producing durable and reliable enclosed cargo trailers. By focusing on robust construction methods and quality materials sourced directly from the factory, they deliver a product that stands up to the rigors of daily use. Their commitment to offering a wide array of customizable options ensures that buyers can specify a trailer that perfectly matches their unique requirements, from basic hauling to fully outfitted mobile operations.

What This Guide Will Cover: Your Path to the Perfect Trailer

This ultimate buying guide will deconstruct the 8.5×14 double axle Diamond Cargo trailer piece by piece. We will explore the critical components of its foundation, the protective features of its exterior, the functionality of its access points, and the potential of its interior. We’ll also cover wheels, braking systems, and crucial considerations like financing options, ensuring you have all the information needed to select and specify the perfect trailer.

The Foundation: Understanding the 8.5×14 Double Axle Advantage

The longevity and performance of any cargo trailer begin with its foundation. The chassis, axles, and frame are the unseen heroes that bear the load and withstand the stresses of the road. Diamond Cargo prioritizes a robust structural design to ensure your investment is built to last.

Unpacking the “Double Axle” Benefit: Stability and Weight Distribution

The term “double axle” (or tandem axle) is a key feature of this trailer’s design. Utilizing two axles instead of one dramatically increases stability, especially at highway speeds and in crosswinds. This configuration distributes the weight of the cargo more evenly across four tires, reducing the load on any single component and providing superior braking performance. It also offers a crucial safety redundancy; if one tire fails, the other on the same side can temporarily support the load, allowing for a safer stop.

Axle Capacity Explained: Tandem 3500# Dropped Leaf Spring Axles vs. 5200lb Axles

The standard configuration for an 8.5×14 trailer typically includes tandem 3500-pound dropped leaf spring axles, providing a Gross Vehicle Weight Rating (GVWR) of 7,000 pounds. The “dropped” design lowers the trailer’s deck height for easier loading. For those hauling heavier equipment, upgrading to 5200-pound axles is a popular choice, increasing the GVWR to 10,000 pounds or more. This upgrade is essential for safely and legally transporting denser cargo.

The Backbone: Tubular Steel Main Frame and Floor Crossmembers

Diamond Cargo utilizes a heavy-duty tubular steel main frame, a design superior to the C-channel or I-beam frames found on some economy trailers. A tubular frame provides exceptional torsional rigidity, resisting twisting and flexing under heavy loads. This structural integrity is supported by floor crossmembers, typically spaced 16 inches on center, which create a strong, stable floor capable of supporting concentrated weight from vehicles or heavy pallets.

Tongue Design: Triple Tube Tongue, Extended Tongue Options, and Tongue Jack Types (Manual Crank)

The trailer tongue connects the trailer to your tow vehicle and must withstand significant forces. A triple tube tongue design offers enhanced strength and durability over simpler A-frame designs. For those who need a sharper turning radius without the trailer contacting the tow vehicle, an extended tongue is a valuable option. These trailers come standard with a reliable manual crank tongue jack for easy hitching and unhitching.

Exterior Durability and Protection for Your Precious Cargo

The exterior of an enclosed cargo trailer is its first line of defense against weather, road debris, and potential theft. The choice of materials and construction techniques directly impacts the trailer’s lifespan and the safety of the contents within.

Siding Options: Aluminum Exterior, Poly Core Panels, and Semi-Screwless Finishes

The standard exterior is typically a durable baked enamel aluminum sheet. A popular upgrade is Poly Core, which bonds the aluminum to a solid polyethylene core, significantly increasing resistance to dents, dings, and “oil canning” (waviness). A semi-screwless finish, where screws are only visible on the vertical seams, offers a cleaner aesthetic and fewer points for potential water intrusion compared to a fully screwed exterior, balancing appearance with structural integrity.

The Roof: Galvalume Roof for Superior Weather Protection

The roof is arguably the most critical component for weatherproofing. Diamond Cargo trailers often feature a one-piece Galvalume roof. Galvalume is a steel sheet coated with an aluminum-zinc alloy, offering superior, long-term corrosion resistance compared to traditional galvanized steel. The one-piece design eliminates seams, which are the most common points for leaks to develop over time, ensuring your cargo stays dry.

Front-End Defense: Diamond Tread Stone Guard

The front of the trailer faces a constant barrage of rocks and debris kicked up by the tow vehicle. A 24-inch diamond tread stone guard, made from durable aluminum checker plate, is a standard feature that protects the front aluminum siding from costly impacts and cosmetic damage, preserving the trailer’s appearance and integrity.

Underbody Protection: Asphalt Undercoating Paint

Protecting the trailer’s steel undercarriage from moisture and road salts is critical for preventing rust and corrosion. An application of asphalt undercoating paint creates a protective barrier on the main frame and crossmembers. This simple but effective feature is vital for long-term durability, especially in regions with harsh winter weather.

Access and Security: Doors, Ramps, and Locks

How you get your cargo in and out of the trailer is a primary consideration. The configuration of your doors and the quality of your locks determine the trailer’s day-to-day usability and the security of its contents.

Rear Door Configurations: Ramp vs. Double Barn Doors (and Rear Door Opening dimensions)

Buyers can choose between two main rear door options. A spring-assisted ramp door is ideal for rolling equipment, motorcycles, or dollies, providing a seamless transition into the trailer. Double barn doors swing outward, allowing for forklift access and the ability to back up flush to a loading dock. The rear door opening on an 8.5-foot wide trailer is typically around 90 inches wide, providing ample clearance.

Side Door Convenience: Bar Lock Side Door for Easy Access

A side door provides quick access to the interior without needing to open the main rear doors. A standard 36-inch side door with a robust bar lock offers enhanced security over simpler RV-style latches. This type of lock provides a more secure closure, acting as a significant deterrent to theft and ensuring the door remains firmly shut during transit.

Security Features: Ensuring the Safety of Your Cargo

Beyond the standard bar lock, security can be enhanced with high-quality puck locks or hasps that shield the padlock shackle from bolt cutters. The enclosed nature of the trailer itself is a primary security feature, keeping your valuable cargo out of sight. Proper locking of the hitch coupler is also essential to prevent the entire trailer from being stolen.

Vents for Airflow and Climate Control

Proper ventilation is crucial, especially when hauling vehicles that may have fuel fumes or materials that off-gas. A pair of plastic side vents, or an upgraded roof vent, allows for passive airflow that helps regulate temperature and removes potentially hazardous fumes, protecting both your cargo and your health when working inside.

Interior Design and Functionality: Making the Space Work for You

The interior of your cargo trailer is a blank canvas. With the right specifications for height, flooring, and wall structure, you can optimize the space for efficiency, durability, and cargo security.

Interior Height: Maximizing Usable Space

The standard interior height for an 8.5×14 trailer is often 6 feet 6 inches (78 inches). This is sufficient for most people to stand comfortably and accommodates common equipment like UTVs. However, opting for additional height (e.g., 7 feet) can be a game-changer, allowing for taller cargo, the installation of overhead shelving, or more comfortable working conditions for a mobile workshop.

Floor Solutions: Standard Plywood vs. Rubber Coin Flooring

The standard flooring is ¾-inch plywood, a strong and cost-effective material suitable for most applications. For a more durable, slip-resistant, and easy-to-clean surface, consider an upgrade to rubber coin flooring. This is an excellent choice for trailers used to haul vehicles, as it provides superior traction and is resistant to oil and chemical spills.

Wall Structure: Wall Members, Wall Studs, and Ceiling Studs for Interior Finish

The interior walls are typically finished with ⅜-inch plywood, attached to wall studs spaced 16 inches on center. This same spacing is used for the ceiling studs. This sturdy framework allows for the easy installation of cabinets, tool racks, and shelving. The consistent stud spacing provides a solid foundation for customizing the interior to your exact needs.

Cargo Management: D-rings, E-Track, and Wheel Chocks for Tying Down Precious Cargo

Securing your cargo is non-negotiable. The most basic option is floor-mounted D-rings, providing strong anchor points for ratchet straps. For ultimate versatility, E-Track systems can be installed on the floor and walls, offering countless tie-down points along the track’s length. For motorsport enthusiasts, removable wheel chocks are essential for securing motorcycles or other wheeled vehicles.

Wheels, Tires, and Braking: Critical for Safety and Performance

The components that connect your trailer to the road are among the most important for safety. Understanding your options for tires, wheels, and the braking system ensures a safe and reliable towing experience.

Tire Choices: Radial Tires vs. Bias Ply and the Importance of Tire Ply Rating (e.g., 6 Ply)

Radial tires are the modern standard for trailers, offering better heat dissipation, a smoother ride, and longer tread life compared to older bias-ply designs. The tire’s ply rating (e.g., 6 Ply or Load Range C) indicates its strength and load-carrying capacity. It’s crucial that the combined capacity of your tires meets or exceeds the trailer’s GVWR.

Wheel Options: Steel vs. Aluminum Wheels

Standard trailers come equipped with durable and affordable steel wheels, often in a silver or black modular design. For a more premium look and a slight reduction in unsprung weight, aluminum wheels are a popular upgrade. While more expensive, they offer enhanced corrosion resistance and can significantly improve the trailer’s overall appearance.

The Braking System: Electric Brakes and Safe Towing Practices

A double axle trailer of this size is equipped with electric brakes on both axles, a critical safety feature. These brakes are controlled by an in-cab brake controller in your tow vehicle and are essential for stopping the combined weight of the vehicle and trailer safely. A breakaway kit, which activates the trailer brakes if it detaches from the tow vehicle, is also a standard and legally required safety device.

Bolt Pattern and Tire Maintenance Tips

The standard wheel bolt pattern for 3500-pound axles is 5 on 4.5 inches. Regular trailer maintenance is key to safety. This includes checking tire pressure before every trip, inspecting tires for wear or damage, and torquing the lug nuts to the factory specification periodically. Proper maintenance ensures the long-term reliability of your wheels, tires, and braking system.

Conclusion

The 8.5×14 double axle Diamond Cargo trailer represents a powerful combination of size, strength, and adaptability. By understanding the core components—from the robust tubular steel frame and dual axles to the weather-resistant Galvalume roof and customizable interior—you can confidently specify a trailer that will serve as a reliable partner for your business or passion. Key decisions revolve around axle capacity to match your cargo weight, door configurations for optimal access, and interior features that enhance functionality.

Whether you need a basic hauler or a fully customized mobile workspace, this trailer provides the ideal foundation. Before making your final decision, carefully consider your primary use case, potential future needs, and available financing options. By investing in a well-specified, high-quality enclosed cargo trailer, you are not just buying a box on wheels; you are acquiring a durable asset designed to protect your valuable cargo and support your goals for years to come.