The Truth About Wheel Weight Ratings and Testing

Do you know what the max weight rating of the wheels on your truck is? More importantly, do you know how the wheel was tested to receive that rating, or if it was physically tested at all? While it sounds crazy, there is no requirement for testing, standards, or general safety specs a wheel must meet in the US, and that leaves a huge opening for false claims or lack of testing. 

That wasn't going to cut it for us at Foundation Wheels, so we sent our wheels out for third party testing at a facility that tests OEM wheels for Ram, Ford and GM to the most stringent standards. Our 395 HD passed hundreds of thousands of brutal test cycles to receive a SAE J2530 rating at 4,500lbs per wheel with a 37/12.5 tires and a large margin of safety. 

Interestingly though, this isn’t a rating you see on most aftermarket wheels because nobody does it. In this article we’re going to discuss the industry standard practices for weight rating, what the SAE J2530 test is, and share the results of our 395 HD testing in more detail because we’re pretty proud of them.

If you’re shopping wheels for your HD truck, you'll see manufactures claim a specific max load weight rating for their wheels. The interesting aspect to these claims is that there’s really no industry wide standard for testing, transparency for how that testing is performed, or even a requirement for that testing to be performed in the first place. For the vast majority of brands, testing is done primarily via virtual FEA analysis. 

That means the wheel design is plugged into a CAD program, and then virtually tested on a computer to discover weak points and a general failure point. This of course is all theoretical calculation, and doesn’t really factor fatigue of the material over time or the tire size used on the wheel. That final factor of tire size is vital, as is testing a wheel physically in the real world where it will be used. 

If a brand wants to take thing a step further, they can have their wheel factory perform structural testing. This is normally done overseas, and with a stock size tire. Most major name brands are testing not with 35s, 37s, or 40s like they show in marketing, but with a stock size tire. As you can imagine, the load dynamics, stress, and failure point would be quite different between wheel with a stock size tire and a wheel with a heavy 37” MT tire. The irony is that a combination of FEA analysis and possibly a stock tire test is what determines almost every wheel's weight rating. That’s not exactly assuring if you have 37s or 38s on your wheels while towing a trailer, and your wheel was never rated using that size tire or even physicality tested.

With new wheel brands popping up every day, it’s tough to trust the manufacturing process and weight ratings since there is no required industry standard. We’re also one of these new brands, but we want to do things differently. That’s why we sought out a better, more trustworthy testing process.

Our search for a US based, third party testing service led us to a Michigan based company called ITS. This is the testing lab responsible for testing and rating most OEM wheels to the SAE J2530 standard. They test and certify the wheels used by major OEM brands like RAM, Ford, and GM, among others. If you want a legitimate test of your wheel's strength, ITS is the place to go. The goal of this test lab is to use a standard testing procedure, standardized equipment, US based lab, and the highest level of scrutiny.

SAE J2530 is a three part test. The process is performed with the tire of your choice (we opted for a 37/12.5 to represent the most common customer size) and then ITS  subjects the wheel to a Dynamic Cornering Fatigue test, Dynamic Radial Fatigue test, and a Lateral Impact test.

The first Rotary Fatigue test is performed at 150,000 cycles, and 9,902nm of load on the wheel. This test was performed twice, and our 395 HD saw 8.8mm and 9mm of deflection in the wheel with no failures. A passing result by a healthy margin.

The next test is a 13 degree lateral impact to the wheels with tire pressure at 55psi, striker load of 1,339.5 KG and a drop of 230.12mm. The wheel is then tested and examined for structural damage as well as air pressure loss. Our wheels passed with no damage to the wheel, no loss of air pressure, and only damage to the ring. This is a perfect example of why we chose to make these wheels using a Florm Formed technique, as it makes the barrel extremely strong whether it’s constant load or a sudden impact blow to the wheel. Despite the massive impact, the wheel would have continued on, and the ring served its purpose as a sacrificial item that can take a blow and be replaced.

The Radial Fatigue test is the final and arguably the most grueling test as it runs the wheel at 90psi for 1,850,000 cycles and then again at 96psi for another 1,850,000. The wheel is then inspected after for any structural damage, cracks, loss or air pressure or deformation of the lug but pockets that would cause a loss of torque. Our wheels passed this test with margin as well.

We are proud to state that our wheels have passed SAE J2530 testing standards with a 4,500lb load rating per wheel at ITS' independent USA laboratory with a 37/12.5 tire mounted. This this wasn’t an inexpensive process to undergo, but we felt it was a vital step to ensure we are delivering a product we can be proud of, and customers can trust. We are also proud to state that we are one of the only wheel brands in the off road space that has subjected their wheels to this testing process. While the wheels likely have a failure point much higher than that, we now know there's a healthy margin even with a massive 4,500lb rating.

Our goal is to offer the best wheel we can for the heavy duty pickup truck market, and a wheel that is designed for a 2500 or 3500 truck from end to end. To us, that meant physical load testing, a weight rating higher than any tire offering on the market, testing with a 37/12.5 tire, and sending our wheels to a trusted laboratory in the US. When you see a Foundation wheel with a 4,500lb load rating stamped into the spoke of the wheel, now you know the story of how we got there, and know you can trust that rating. If that isn’t enough, these photos and this video of Greg A jumping his 7,500lb truck to flat with our wheels should help.