The Best Roof Bars for a TentBox

A question we frequently get asked is, 'What roof bars do we recommend for TentBox roof tents?' If you’re thinking of adding a TentBox to your car for spontaneous weekend escapes or serious overlanding adventures, you’ll need roof bars you can trust. The right bars make all the difference in terms of safety, ease of fitting, and compatibility with your TentBox model.

Introduction to car roof bar systems

Car roof bars (also known as roof racks or cross bars) are a versatile accessory that allow you to carry extra gear on your vehicle's roof, such as bikes, skis, cargo boxes, or TentBox roof tents :) They form the foundation for most roof-mounted storage solutions.

Importantly, not all roof bars fit all cars. The type of roof bars you need depends on your vehicle's roof style, which can vary widely. Common roof types include:

Raised roof rails: Bars run along the length of the roof, with a gap between the rail and the car roof.
Flush/Solid roof rails: Rails are integrated and sit flush against the roof without a gap.
Fixed point: Small, pre-installed mounting points on the roof where bars can be attached.
Normal (or naked) roof: Requires a custom-fit system that clamps into the door frame.
Factory fitted: Some car models provide a factory fitted roof bar system already integrated into the car.

There are also different types of bar fixings, which affect how the bars attach to the roof and what kind of loads they can handle. These include:

Clamp-style fixings: Common for cars without rails.
Foot packs with custom fit kits: Tailored to the specific car make and model.
T-track systems: Allow for accessories to be slid in securely along the bar’s track.

When choosing roof bars, it’s important to select a system that matches both your vehicle type and intended use and always ensure it's installed correctly for safety and performance.

Understanding roof Load Capacity

All vehicles have a roof weight limit. This is the maximum weight that can be safely placed on the vehicle roof. Roof weight limits are usually expressed as Dynamic Weight limits, which is the maximum weight you can put on the roof whilst driving. Static weight limits are usually 3X or 5X the dynamic limit. Always check your vehicle’s roof load limits:

Dynamic load: The maximum weight your roof can carry while driving (includes the roof bars and TentBox).
Static load: The maximum weight your roof can support when stationary (usually much higher and accommodates the TentBox plus occupants).
You must not exceed these limits and should always refer to your vehicle manual for exact figures.

Which bars do you recommend for roof tents

Our team has over a decade of experience fitting roof bars to vehicles and exclusively recommends Thule roof bars for all installations where roof bars are not currently present.

Thule is a Swedish company known for designing and manufacturing premium outdoor and transportation products, including roof racks, bike carriers, cargo boxes, and other travel gear. Founded in 1942, Thule has built a strong reputation for innovation, safety, and sleek Scandinavian design. Thule roof bars are widely regarded as high-quality, durable, and user-friendly. They are designed with aerodynamics in mind to reduce wind noise and drag. The bars are rigorously tested for safety and performance under extreme conditions. While they are often more expensive than competitors, users appreciate their reliability, ease of installation, and compatibility with a wide range of vehicles and accessories.

Why Choose Thule for Your TentBox?

Exceptional quality: Made with robust materials that withstand years of use.
Tested load ratings: Ideal for carrying the dynamic weight of your TentBox safely.
Quiet and aerodynamic: Reduced wind noise on long trips.
Wide compatibility: Fits most cars with the correct foot pack.
Easy installation: T-slot channels simplify securing your TentBox clamp

Thule Roof Bars for TentBox Installation

Here at Redknot, our team fit either the Thule SquareBar or Thule WingBar Evo. Both are great choices from a safety and load rating perspective but there are some differences between the bars in aesthetics and sound.

Thule SquareBar

The best value Thule bars for TentBox installation:

Load rating: Around 100kg dynamic.
Design: Classic, simple square steel bar with polymer coating.
Pros: Good value and tough

Great value, excellent load rating and safety. Counter to manufacturer claims, our customers report these bars actually are quieter than aerodynamic bars when a tentbox is fitted to the roof as they don’t create a whistling wind channel in between the roof and the tentbox which the aerodynamic bars do.

Thule WingBar Evo

Thule is often the first name people think of, and with good reason. The Thule WingBar Evo is one of their best options for TentBox users.

Load rating: Typically 75 - 100 kg dynamic (check with us).
Design: Aerofoil shape can create a whistle style opening once a tentbox is fitted potentially generating wind noise on some vehicles.
Build: Aluminium, corrosion-resistant.
Why it’s good: Proven brand, super easy to find spares/adapters.

Good for anyone who wants a refined look while carrying a TentBox with total peace of mind.

Thule vs Summit Bars

When choosing roof bars for your TentBox, it's worth directly comparing Thule and Summit, since Summit bars are often seen as a cheaper alternative.

Thule bars are premium for a reason. They’re rigorously tested for load-bearing strength, corrosion resistance, and quiet, aerodynamic performance. They use higher-grade materials, have precise engineering, and offer T-slot channels that make securing your TentBox simple and rock-solid. All Thule bars are load rated to 100Kg (220lbs)
Summit bars can be appealing on price, but they’re not on the same level in terms of build or durability. User reports suggest that many of their generic options may flex or underperform when loaded with a rooftop tent, especially larger models or when occupied overnight. All Summit bars are load rated to 75Kg (165lbs)

For serious TentBox use, especially if you’re planning to sleep in it regularly, we don’t recommend Summit bars. The extra strength and engineering of Thule bars give you much greater confidence and safety on the road.

Our advice: If you’re investing in a TentBox, it makes sense to pair it with roof bars that match its quality. Go with Thule SquareBar Evo or WingBar Evo, for long-lasting, worry-free adventures.

Final Thoughts

When it comes to fitting a TentBox, Thule roof bars are the gold standard. Our team sells and fits Thule roof bars every day. If you want advice on which Thule bars will best fit your specific car and TentBox model, just ask, we'll be happy to help you figure it out!