How a bull bar is made…from concept to the front of your 4×4

how a bull bar is made

When it comes to protecting the front-end of your rig, nothing beats a bull bar. MotoFomo talked with 4×4 accessories brand, TJM, about what goes into making a bull bar.

Like an awning or a set of driving lights, no 4×4 build is complete unless you’ve got a bull bar on the front. I mean, it’s there for protection, of course, but also for mounting UHF antennas, driving lights and winches. And let’s not forget, looks. A bull bar has to suit your rig.

But have you stopped to think about what goes into making a bull bar? Probably not. And we can tell you that they’re not all created equal. Here at MotoFomo we’re all about passion and showcasing those brands that go that extra mile to ensure you lot get a product you can rely on.

With the new Isuzu D-MAX being the current pick-up of the hour, we decided to sit down with the design and engineering team at TJM and talk about the process behind designing and building a bull bar for a brand-new vehicle.

Being a brand-new vehicle with a lot of advanced active safety systems, TJM head of product development, Darren Piper told MotoFomo the D-MAX proved to be one of the biggest undertakings from a design and engineering perspective the brand had managed in a long time, and that was largely down to a desire to be the first to market.

“TJM is known for uniquely styled accessories that enhance the look and functionality of a vehicle, so we wanted to give that to customers as early as possible with the new D-MAX,” Darren told MotoFomo.

At TJM, Darren told us, the average bull bar development cost is well into the six-figure realm. This can vary heavily if it has to deal with a number of variants from the manufacturer, especially if there are front-end differences between models. The final numbers are still being crunched on the costs involved in the development of the full suite of products for the D-MAX, but let’s just say it’s far more than you might think.

How does the development cost of a bull bar add up to that much I hear you say, well, let me take you on a journey of development.

Finding out about a new vehicle

A common misconception is that aftermarket accessories manufactures have close relationships with vehicle manufacturers, sometimes they do and sometimes they don’t. Darren, the head of product development at TJM told MotoFomo most aftermarket brands tend to source information about new vehicles through media releases and what is published on news sites, like MotoFomo. 

“Occasionally we get some level of a heads-up about a vehicle because of our relationships with vehicle manufacturers and trade customers.”

For the product team at TJM, as soon as they hear the public announcement they head off to visit one of the local dealerships to secure the earliest possible vehicle to ensure they can start the process as quickly as possible.

In some cases, the first release may not be in Australia. In the case of the D-MAX, it was first available in Thailand with a long wait until it arrived in Australia. The TJM team purchased a vehicle in Thailand, created a 3D model and then pulled it apart, all before putting it all back together. This allowed the team to begin design work prior to the vehicle arriving in Australia.

Hands on time with a vehicle

Getting hands-on time with a new vehicle is vital, as it allows the engineering team to scan and then use 3D imaging to create detailed renders of the vehicle. This helps the design team develop the look of bar work without having to pick up a lump of metal.

Three-dimensional scanning also helps the team work around safety features and cooling ducts when it comes to the placement of things like tabs for UHF antennas and driving lights, as well as any styling cues the TJM team need to work with. And it allows them to strip away body panels with a computer to show mounting points. It’s a vital part of the process.

And it’s not a case of one size fits all, because often designers and engineers will need to work with different variants. It is not uncommon for top spec vehicles to have a different bumper, variations on the headlight style or slightly different cut lines, meaning everything has to be checked to ensure it works across multiple variants.

Vehicle testing

Everything begins with road testing. The TJM engineering team gets behind the wheel to get comfortable with the vehicle. For the D-MAX, careful attention was paid to testing out various advanced safety systems, like lane-keep assist, forward radar and impact detection. 

According to Design Team Leader (Body Exterior) Luke McLoughlan, the engineers pretty much just drive around in the vehicle for a week, drinking coffee and collecting data.

Once the basics have been studied, the engineering team moves into more in-depth testing in controlled environments. They run through a range of collision avoidance tests, seeing what the vehicle will do when presented with sudden obstacles and working out the vehicle’s line of sight. “In some cases, the manufacturer has outlined some of the information in the manual, however in most it is up to us to ensure that we totally understand the vehicle before we can begin to create any additional products for it,” said Luke.

Design and development of the accessories

“We get it right first time about 75% of the time. Usually, it might just be that we have to adjust some lines a bit, in rare cases and in the case of the D-MAX we scrapped the first model and started again from scratch”.

Luke McLoughlan – Design Team Leader (Body Exterior) TJM

The design and development of bull bars and accessories starts as soon as the hands-on scanning is complete. Focus areas are usually mounting points and ensuring they won’t affect safety systems. The ‘skin’ of the bull bar comes later.

“The team starts by looking at the ‘DNA’ of the particular bar we are designing. For example, the TJM Outback bar needs to have two aerial tabs, integrated recovery points, mounting for spotlights, winch facilities and a black powder coat finish. Not to mention that it still needs to stay ADR compliant,” Darren told MotoFomo.

There often has to be a compromise between the feature set of a bar and what can actually be accomplished, with all the new technologies it is becoming harder and harder to fit things like driving lights, winches and aerials onto bull bars.

“A lot of OEM bars are just dropping these features, so it is a great opportunity for us to develop a better product,” adds Luke.

In the case of the TJM, the compromise for the D-MAX Outback bar was that the Winch had to have synthetic rope. If you use the rollers that are required for steel cable, they will interfere with the number plate mounting and that can interfere with the active safety systems, Darren explained.

The focus then turns to the vehicle itself and what will look good on it. 

“TJM has a real focus on ensuring that our bar work fits the style and lines of the vehicle,” said Darren. 

“We work hard to integrate the style of the bar with the style of the vehicle, and we believe it really shows in the end product.”

When enquiring about the success rate of the design team, Luke said: “We get it right first time about 75% of the time. Usually, it might just be that we have to adjust some lines a bit, in rare cases and in the case of the D-MAX we scrapped the first model and started again from scratch”.

Prototype testing

Testing is a massive part of the process. Once a bar is developed, TJM then conducts a series of rigorous tests.

TJM has a large testing facility at its head office in Brendale, QLD. It has the facilities to conduct load testing, shaker tests (for corrugations) and a test with a pendulum swing for airbag compatibility. Honestly, do yourself a favour and go watch the video that TJM made of its Pendulum and Load rating tests. With these tests, the team is looking to ensure a correct transfer of energy through the mounting systems and ensuring there is enough force that the airbags should deploy when they are meant to. Just as importantly, avoid deploying in low-speed impacts. TJM also has access to high-speed testing facilities in Melbourne for when more advanced and complex testing is required.

After the prototype testing is conducted, the bars are then mounted on the vehicle to check their integration with the technology. The integration testing is similar to the initial vehicle testing in that the TJM team spends a lot of time behind the wheel of the vehicle ensuring nothing interferes with the original performance of the vehicle. Luke even discussed the team will go to the point of running different coloured sleeves over antennas to ensure the camera isn’t confused by them.

Further to that, they will also run testing with dummies, kangaroos and stationary objects to make sure all the systems perform flawlessly and are perfectly safe for the average punter.

Final production specs and modelling

By the time it gets to the final construction phase, usually around three months have elapsed with countless hours of driving, many hundreds of computer models tested and numerous prototypes built. In the case of the D-MAX, Darren, Luke and the 50 or so other TJM staff involved were able to have product in store ready to go weeks after the launch of the vehicle.

As we said at the beginning of this article, not all accessories makers go to the same effort or spend the money on testing that the major brands do. So, when it comes to buying your next bull bar or rack, make sure you’re buying from a brand that invests the time and effort to build a quality product you can rely on.

You can check out more details on the TJM barwork by getting in touch with your local TJM store.