Michelin proves it: (Tire) size does matter

Now I’ve seen a lot of tires in my lifetime. And growing up in the South, I’ve heard most of them referred to as “tars.”

I’ve seen new tires, white-wall tires, flat tires and tires all torn up, littered along the side of the road. I’ve seen tires turned into swings and fences and fashioned into flower pots.

But I can tell you this: I’ve never seen tires like the ones I witnessed the other day when I had the most pleasurable opportunity of being inside Michelin’s US7 tire plant in Lexington.

But let’s back up.

Like you perhaps, I spend a significant amount of time on the road. My normal route takes me up and down around where I-26 and I-77 merge just south of Columbia. Rolling along in my truck, I often see 18-wheelers hauling shipping containers to the Charleston port. Peeping up out of those topless containers are four – sometimes five – eye-popping, enormous tires.

Recently. my curiosity finally got the best of me and I decided to find out more about these bad boys.

So, the official name of these big, round orbs of rubber is Earthmover tires.

They are, according to official info from the Michelin folks, “used on off-highway haul trucks and rigid dump trucks for high-production mining and heavy-duty construction applications worldwide.”

That is to say, these tires are the stuff of little boys’ dreams – big dang tires on big dang trucks doing big dang jobs.

I asked Mary Ann Kotlarich, Michelin’s commercial public relations director, if it was safe to say these tires are the biggest in the world.

“Yes,” she said.

And how big is that?

Well, first, here are my layman’s observations.

You can easily stick your fist inside the tread. If you stick your head inside one of these tires and say something, you’ll hear an echo. Furthermore, if you’re a tire-swing type person, you can’t imagine anything finer than pumping your legs and swinging into the treetops in one of these babies.

As for official statistics? Here’s a list from Michelin.

▪ Michelin’s XDR 3 63-inch tires can weigh as much as 12,000 pounds and are about 13-feet tall and five-feet wide. They have a load-carrying capacity greater than 100 tons. Six of these tires are used on a massive rigid dump truck that weighs as much as 600 tons with payload.

▪ It takes 36 hours, from start to finish, to produce one tire.

▪ About 80 percent of the tires produced at the Lexington plant are exported to Canada, Australia, South America, Europe, Asia, Africa and other places.

▪ The life of a tire depends upon the conditions in which they operate and the hours they are used. A 24/7 mine with aggregate roads will see very different tire life than a construction site operating on soil for a 10-hour day.

▪ Yes, these tires can go flat. Because of the loads they must be carefully monitored for tire pressure and temperature so they do not overheat. Heat is the enemy of tires. An advanced monitoring system, called MICHELIN MEMS 3, is built into the tires. “They are ‘smart’ tires,” Kotlarich said. “Technology is built into the tire so that the tire can communicate with the manager of the mine or the quarry.”

So, like me, you’ve got to be wondering how much one of these tires cost.

I’m told about $60,000.

I asked Stan Pech, the US7 plant’s quality manager, if these tires were recycled. He said yes, including being turned into feeding troughs for farm animals.

At the end of my plant tour, on a recent Wednesday, Pech and I stood on tall scaffolding, watching four Earthmovers being lowered into a shipping container bound for the coast. The process is a careful one.

“We treat ’em like eggs,” Pech said. “By Saturday, they’ll be on a vessel.”

Then we talked about how working around these big tires must be the stuff of little boys’ dreams, mesmerizing even for adults like us.

Pech smiled.

“It never wears off,” he said. “The size of these things is always amazing.”

This story was originally published January 30, 2017 at 1:50 PM with the headline "Michelin proves it: (Tire) size does matter."