Every auto enthusiast knows the impact of custom rims. They can turn an everyday ride into an eye-catcher, and a project vehicle into a show winner. Beyond personalizing the look of your ride, though, there are several key aspects to factor into your wheel selection.
Improving performance is an another advantage of aftermarket wheels. Wider rims allow you to fit fatter tires with a bigger contact patch for better handling, along with a quicker hook-up on hard acceleration. Also, lightweight alloy wheels, if they're not enormously larger in diameter, reduce unsprung weight. That means less poundage for the suspension to absorb on uneven pavement, or for the brakes to slow down.
All sounds good in theory, but getting down to the details can be daunting. For some expert advice, we spoke with a long-time show-vehicle builder, Larry Weiner of Performance West Group. In his many years of fitting wheels on a multitude of show cars and trucks, he's hit more than a few bumps on the road. These include everything from tires rubbing the fenders to wheel hoops not clearing the calipers, and from weak construction to overloaded bearings. So he's well qualified to share his hands-on experiences, and provided several pointers when picking out a set of radical rims.
Starting with the basics, make sure there's enough room under the fenders. For that, "Offset is really important, a critical component," Weiner points out. "It locates the rim in wheel well, and if it's not correct, it'll push to the outside of the car." (If you're not already familiar with this term, offset is the distance from the backside of the wheel mounting pad to the outside of the rim flange.)
While some custom cars and trucks have an "outboard" type of mounting, be advised that the extra side load on the bearings can be unsafe and even illegal in some states. Despite this potential problem, "hellaflush" is now a popular approach, where the wheel nearly touches the fender lip and also has an extreme camber angle (tilting inward at the top).
If that's the look you want, first make sure your wheel shop determines whether the size will scrape or not. After all, "You don't want to get stuck with a set of expensive rims that won't work on your vehicle," Weiner advises.
Also, don't assume that the room inside the wheel well is the same on each side. A staggered mounting of shocks (for better handling), along with other suspension components, can intrude on the available space. So measure both sides of the car before buying different sizes of rim and tires.
Speaking of measuring, diameter is another key dimension to evaluate, but not solely from wheel-fitment standpoint. If you plan to install bigger brakes than stock, especially on older wheels, you might not have enough clearance. Most muscle cars in the Sixties used rims that are typically 14- or 15-inches, too small for most modern disc brake systems. Also, keep in mind that the wheel spokes need to clear the calipers as well, usually by at least 1/8th of an inch.
As for going larger in diameter, it's an entire article subject in itself, but keep in mind that when you step up to 17s, 18s or more, you'll need tires too, which can affect the calibrations on the speedometer, odometer and ABS (Automatic Brake System).
Also, some customizers prefer "staggered fitments", with bigger rims in the rear than up front. The margin of difference between the front and rear has to be fairly slim, otherwise it can confuse the ABS, causing brake wear and handling issues. On many makes of wheels, however, you can run rear tires that are wider than the front, while maintaining the same diameter front and rear, so there are no issues with the speedometer, cruise control or ABS.
Obviously a larger diameter can also create clearance issues, so a suspension lift might be required on a truck (or that odd style of car with wagon wheels called a "donk"). Larger wheels can also add considerable weight, even if they're made of a lighter alloy than the stock rims. If that's the case, you might need to upgrade the brake system as well to compensate.
Note, too, that forged wheels are stronger than cast ones, so if you can afford them, they're a better choice when going to bigger tires with a shorter sidewall. They have less less cushion when you hit a bump or pothole, so make sure you buy high-quality rims.
Tires and Lug Nuts.
Speaking of tires, as noted at the outset, you can go wider, but make sure they're compatible with the recommendation of the tire manufacturer based on size. The aspect ratio (relationship between a tire's height and width) is very important and can be a safety issue. When you shop for tires, check if they are compatible with the wheels, especially on trucks, where having the correct load rating is important as well.
As noted at the outset, getting the right look is a big part of upgrading to custom wheels, so you need to keep the maintenance requirements in mind as well. "Billet is a lot of work to maintain," Weiner points out. "Once oxidized, it looks lousy and need polishing. So if you want billet rims, go with a clear coat for zero maintenance." Also he says to be aware that while chrome-plated cast wheels are relatively inexpensive and look great when new, in damp climates the surface tends to get pitted, losing its luster.
Another detail to remember: lug nuts. Will the factory fasteners fit your custom wheels? If not, you'll need to get a new set, and see if you'll need a need special adaptor tool to fit them. Note, too, that stud sizes on newer vehicles are larger, so older lug nuts might not fit. Also, to protect your investment in premium wheels, locking lug nuts are a wise choice (though not a guarantee of protection from a persistent wheel thief).
How about converting a four-lug hub so it can accept a five-lug wheel? (Or even an eight- to a ten-lug wheel on a large pickup.) You'll need to either switch out the front hubs and axle, or use billet adaptors. If you go the latter route, use a single-piece unit, the thinnest possible (about an inch), so the wheels don't stick out too far.
Overall, follow these basic tips, and you'll save time and money when shopping for custom rims. After all, knowledge is your best ally when buying alloys.