This is what the long spikes on semi truck wheels actually do and they're not just for appearance

Semi trucks with those long, pointy spikes on their wheels look like something out of a Mad Max movie.

If you’ve ever been stuck next to one in traffic, you’ve probably inched your car a little farther away.

They spin, they shine, and they definitely look sharp enough to do damage.

But what they’re actually for is way less dramatic than you’d think.

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What these long spikes actually do

To understand the wheel spikes, you first need to know what’s underneath them.

Every wheel is held onto a vehicle by thick metal fasteners – basically very strong bolts that keep the wheel locked in place. 

On big semi trucks, those bolts are large and exposed.

Because trucks drive through rain, mud, road salt, and extreme heat, those exposed metal ends can rust over time. 

When that happens, it makes maintenance harder and removal more difficult later on.

The spikes you can see aren’t the bolts themselves; they’re hollow covers that slide over the ends of those fasteners, and their main job is to protect the metal underneath from corrosion and dirt.

The long, pointed shape isn’t required for protection, though; that’s mostly style. 

Truck customization is a big part of the culture – as you’ll see in the video above – and some drivers like the bold, shiny look.

But here’s the surprising part: most of those spikes aren’t solid steel. 

They’re usually made from plastic, rubber, or thin aluminum. 

They’re pressed on and held in place by friction.

So if a car were to brush against one, it would likely crack or pop off rather than slice through a door. 

That said, the strong metal parts underneath are far tougher than the decorative cover.

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Why semi truck wheel spikes still cause debate

Even though they’re mainly protective covers, these spikes still spark arguments.

Some people claim the spinning chrome makes trucks easier to notice in blind spots. 

Others think they’re distracting or unnecessary.

And laws regarding their use vary depending on location. 

For instance, Hawai’i limits how far spikes can stick out. 

While Washington has rules against wheel parts that could pose hazards to pedestrians and cyclists. 

Other states focus on overall vehicle width, and many don’t regulate them at all.

Some trucking companies ban them internally, too, because there is one real concern. 

In a side-impact crash involving a cyclist or pedestrian, any hard projection could increase injury risk. 

That’s why certain areas take a stricter approach.

But for most drivers sharing the highway, those long semi truck wheel spikes aren’t built to damage anything. 

They’re protective covers designed to fight rust.

Just shaped in a way that makes a serious visual statement.

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