The Crane That Lost Its Rim Every 90 Days – And Why Corrosion Wasn’t the Real Problem

A farm operator in Nebraska called us last year. His fleet of mobile cranes kept losing rims to what they called rim flange corrosion. The paint was peeling. The metal looked rusted. The maintenance team had replaced three rims in eight months on the same crane. The operator wanted a better coating.

We asked to see the crane’s duty log instead of the rim invoices.

12-hour night shifts, 32°C ambient, wet ground that never dries

The crane worked in a grain handling yard with heavy seasonal demand. Night shifts ran 12 hours, from 7 PM to 7 AM. Ambient temperature still hit 32°C at midnight. The crane moved between concrete pads and wet soil, and the rim flanges stayed damp for hours after every rain. The operator we rode with made about 15 hard turns per night. Each turn dragged the tire sidewall against the rim flange, rubbing off any protective coating.

“The rim looks fine when we start,” he said. “By morning, the paint is gone near the flange, and the rust starts showing by the third shift.”

We measured rim flange temperatures after a full night shift. On the steer axle, we saw 94°C repeatedly – not hot enough to cook rubber, but hot enough to accelerate corrosion under the paint layer.

Why “better coating” wasn’t the answer

The operator had already tried a zinc-rich primer and a heavy-duty industrial paint. The coating lasted two weeks. The mechanic was frustrated. “Same moisture, same rubbing. Just peels off faster.”

We pulled temperature and humidity logs from the crane’s telematics over three weeks. On nights with high humidity, rim flange temperatures stayed above 85°C for more than eight hours. The coating softened, and the constant sidewall rubbing wore it through to bare metal. Tire wear research confirms that interfacial friction between rubber and rim accelerates when both temperature and sliding frequency are high.The real issue was not corrosion resistance – it was heat‑accelerated coating wear followed by moisture attack. This pattern confirmed that rim flange corrosion was driven by rubbing and heat, not just moisture.

The maintenance supervisor said, “We thought a better paint would fix it.” He wasn’t alone. A similar operation in Iowa had made the same mistake: premium coating on high‑rub, high‑heat duty. The coating failed faster.

What the data finally pointed to

We charted failure rates against turn intensity, not just hours. The correlation was clear: cranes working the busiest grain bays – more turns, tighter clearances – lost rim coating twice as fast as those on straight hauls. The operator’s comment: “I thought rust was about moisture. Turns out it’s about how many times we rub the flange.”

What actually worked (after one failed attempt)

We first tried a softer sidewall compound to reduce rubbing pressure. It helped a little – coating lasted three weeks instead of two – but the failures didn’t stop. So we switched to a bias-ply durability design. Bias-ply construction flexes less at the rim area than radial tires. Less flex means less rubbing between the sidewall and the rim flange. The coating stayed intact. Even without a perfect diagnosis, the bias-ply durability design eliminated rim flange corrosion on the test crane.

After three months, the test crane had zero rim flange corrosion issues. The rest of the fleet had four.

One test crane still ran slightly hotter on the right steer rim. We suspected a minor alignment issue, but the farm never confirmed it because the crane was needed every night. That rim eventually wore out after 5,000 hours – but never corroded.

What the numbers looked like

Over one year, the farm that switched to bias-ply durability design saw:

• Rim flange corrosion frequency dropped by roughly 55%

• Cost per operating hour improved by about 30%

• Unscheduled downtime related to rim issues became rare

The operator’s takeaway: “I used to ask for better paint. Now I ask how much the tire flexes at the rim.”

A few things we never fully proved

We never isolated why the right steer rim ran hotter. Alignment? A bent flange? The farm didn’t have time to chase it, and the rim stopped corroding anyway. Sometimes you don’t get a perfect diagnosis. You get a rim that lasts.

More resources from our partner site

This case focused on rim design and tire flex. For deeper insights into how sidewall construction affects heat and wear at the rim area, see our partner site GREAMARK OTR tires, which offers additional field data on heat management and sidewall durability.

For more field notes, visit RUNGOLD.NET or contact our technical team.