They say wheels can transform a car. You don't have to take anyone's word for it, either. That the Specialty Equipment Market Association (SEMA) dedicates almost 650,000 square feet of exhibit space at its annual convention to nothing but wheels and tires tells us that they're popular.

That got us thinking: We started that trend. Well, you and I didn't do it but our forebears sure did. They started by swapping wheels among cars but soon they cut apart OEM wheels and reversed, widened, and plated the rims prior to welding them back to the centers. Our brethren were the ones who adapted racing wheels to street cars. One of our guys, Lou Senter, an aftermarket parts manufacturer who made alloy wheels affordable for the masses, cofounded the association that devotes all that exhibition space to wheels and tires. What better way to celebrate that than by showcasing the industry's noteworthy rollers?

That's a big order to fill. We have steel wheels, aluminum ones, steel-aluminum hybrids, and others made from magnesium. We figured we'd be safe to cover just the most famous designs, but where do you draw the line there? With nearly a century's worth of popular wheels to cover we could fill a book, if not volumes of books. We had to draw the line somewhere.

At first it seemed easy: Rod & Custom is a somewhat traditional title so do nothing but traditional wheels. But how does one define traditional? Well the early 1970s offers a convenient and somewhat objective break. The recession then pretty much killed the market and by the time it rebounded billet was king and I think we all can agree that billet isn't traditional, at least not yet. That same recession also killed Rod & Custom, drawing the line even deeper in the sand.

That still gives us a lot of ground to cover—too much for one entry, in fact. So we're breaking our focus into three categories: one for steel OEM wheels, another for alloys, and a third for aftermarket wheels, including composites (hybrids with steel rims riveted to aluminum centers).

We admit this is an imperfect account. There's simply no way to cover more than the most popular ones. So we ask you in advance to forgive us if we've ignored your favorite. However, of the wheels we're showing here, all but a noted few are available through the aftermarket, including at the sources listed. In some respects it really is the very best time to build hot rods and customs.

The Balloon-Tire Craze
You've likely encountered some curious wheels at swap meets. If they're like these they date to the late 1920s and 1930s. But unlike wheels common to that era their wider rims mount tires with 16-, 15-, and even 14-inch bead diameters, the last of which didn't come to pass until the late 1950s. Rest assured they're not modified.

The most effective way to increase a tire's traction is to widen it, but in the early days of tire technology that wasn't possible without also increasing the sidewall height. The taller tires that resulted wouldn't fit existing vehicles so the manufacturers went the other way and reduced the rim diameter. The balloon tire was born.

To create a market for these ample tires the tire makers hired wheel manufacturers to build rollers that would adapt them to existing cars. Goodyear had disc wheels stamped for its Airwheel line. Truck-wheel manufacturer Clark Equipment Company made wheels with cast-iron centers for Firestone's Air Balloon series.

We can't say for sure but the riveted-spoke wire wheels that Kelsey Hayes and Motor Wheel Corp. produced may also owe their existence to balloon tire updating (Kelseys as small as 15 inches turn up every so often). Kelsey Hayes definitely produced a lock-ring wire wheel for Firestone according to Jim Lattin, who gathered a complete set to reproduce the Danny Sakai modified.

Without a doubt bicycle maker Cleveland Welding produced the most famous undersized wheels for General Tire. With bead diameters as small as 14 inches, General's Jumbo line was by far the most extreme. And according to the number of those Cleveland Welding wheels still around, the Jumbo was the most popular.

Though aftermarket, these wheels generally aren't considered hot rod or custom-car wheels. Enthusiasts eager to set their machines apart from the crowd might change that, though. These are actually somewhat attractive—at least a far sight better than some of the obscure wheels we've seen bolted to hot rods in the pursuit of individuality.

Stamped-Steel Wheels
Manufacturers like Chevrolet and Packard experimented with disc-type wheels in the 1920s, but their flat profiles were relatively vulnerable to lateral loads. But deep-draw stamping techniques pioneered in the 1930s gave wheels more complex shapes for strength. What's more, the opportunity to choose shapes let carmakers distinguish their wheels from others.

So effective is the stamped-steel wheel that it survives on just about every vehicle made today. Unless they're identifiable as modern, stamped wheels are also generally impervious to trends.