Here’s Why Truck Beds Almost Never Connect To The Cab

Have you ever noticed how nearly all pickup trucks have a visible split between their cabs and cargo beds, so the two aren’t really connected to each other? It might seem kind of odd at first, but there’s an important reason for this, and it goes back to the origins of the auto industry.

In the beginning, cars were assembled with a steel frame as their foundation. They were then built up by adding parts, including the body and, in a truck’s case, the bed, onto that frame. These “body-on-frame” vehicles were known for their strength and durability, but not so much for their smooth travel. Now, I’m not the first Jalopnik writer to drive a Model T, but I can tell you from personal experience that these were indeed rough-riding machines which must have shaken people like fancy martinis on the primitive roads of the time.

The search for a smoother driving experience led to what’s generally considered the first unibody car, the 1922 Lancia Lambda. Unibody vehicles get their name from the fact their bodies and frames are unified into one structure, and they get their better rides from the fact that they’re more rigid than body-on-frame vehicles.

Nowadays, its the demand for maximum functionality over max comfort that makes body-on-frame construction — with separate cabs and beds — so common among trucks.

Unibody vehicles can show a lot of other advantages beyond smooth operation, too. For example, it’s easier to integrate crush zones and other design-based safety features in a unibody vehicle, and unibody vehicles tend to be lighter, so they drink less fuel. The thing is, capability is usually top of mind for truck owners, and the unibody’s rigidity works against it when you’re towing, hauling, or headed off road. 

These situations all demand a certain level of structural flexibility to allow the vehicle to twist without bending or breaking with heavy loads and uneven terrain. If you’ve got 1,000 lbs in your pickup bed, even hitting a pothole could cause the cab and bed to move in different directions relative to each other — and if they can’t move separately, because they’re part of the same unibody, something’s got to give.

Of course, body-on-frame trucks have improved as well, making big gains in efficiency, safety, and luxury. It’s just that they still haven’t found a way to give unibody trucks the peak strength and flexibility of a body-on-frame pickup. That’s why all of the top trucks for towing, hauling, and trail riding still have a seam between the cab and the bed.

Let’s also look at why we had to put the word almost into today’s title — a growing number of open-bed utility vehicles are now being built with unibody construction, including the Ford Maverick, Honda Ridgeline, and Hyundai Santa Fe. 

These trucks are aimed at people who don’t necessarily need the biggest, baddest pickup in town. Heck, the Maverick is even available as a front-wheel-drive hybrid. In addition, automakers like Rivian and Tesla rely on unibody construction for their electric pickups, while Chevrolet uses a sort of mixed setup for the Silverado EV – although the Ford F-150 Lightning sticks with a body-on-frame build.

Regardless, there seems to be a lot less hand-wringing over the two styles in the truck sector. Of course, this might be the case because the SUV market already went through an existential crisis over the difference between a body-on-frame SUV and a unibody crossover. On the other hand, you’ll note that the Ridgeline went from having no separation between its cab and bed in its first generation to having a thick rubberized molding visually separating the two in the second. For some folks, apparently that still counts as a real-truck seam of approval.