One of the most iconic details of the midyear (1963-1967) Corvettes is the use of “knock-off” wheels. The term is typically used as a paraphrase for “reproduction,” but in the sense of these stylish sports cars, it actually is the means for removing and installing them!
Except for perhaps the Opti-Spark distributor used on the second-generation small-block, there may not be any other item offered by General Motors that defined the era, yet brought so much trepidation. Imagine having a pristine paintjob on your Corvette, and each time you wanted to remove or install a wheel, you needed to beat on the center with a hammer. That meant hoisting the heavy tool within close proximity to the car’s fender or quarter-panel’s paint!
If you do it correctly (and many enthusiasts have proven that it can be done), there will be no problems. But, if you don’t, you might lose a wheel. So, to recap – you can bugger up the bodywork on your Corvette by hitting it with a hammer, or you can be driving along and allow your newly-loosened wheel to do it for you. It doesn’t take long to see why some enthusiasts are hesitant to take a set of knock-off wheels lightly.
The Difference In The Details
The original knock-off wheels were produced by Kelsey Hayes for use on the then-new midyear Corvette but were also used on many European autos prior to Corvette adopting them. Knock-offs were even used on some of Carroll Shelby’s creations, but we’re going to stick with the Chevrolet side of things for now.
To say there are a few different types and styles of knock-off wheels would be an understatement. There are the original wheels, which were manufactured for GM by Kelsey Hayes. There are also reproduction wheels that were made by Western Wheel. Other companies have begun reproducing knock-off wheels, with each one being slightly different.
Parts supplier, Corvette America, offers both knock-off and bolt-on style wheels for Corvettes. For judging purposes, enthusiasts are recommended to consult the appropriate judging manuals for their particular year of Corvette. There is a lot of information available as to what is correct and acceptable, more than we can cover here.
One way the OE wheels differ from most of the aftermarket wheels is the omission of the “safety pin” that helps ensure the spinner does not rotate during use. Another thing about the factory wheels for 1963-1967 Corvettes is the understanding that no 1963 Corvettes were shipped from the factory with knock-off wheels. That said, some Corvettes were shown having knock-offs. But, they were limited to the first few Pilot cars or some of the rare race cars sent to those lucky racers who knew the combination to Chevrolet’s back door.
While knock-off wheels were intended to start with the beginning of the midyear generation, a lawsuit against Kelsey Hayes put the project on hold. As it turns out, the early knock-offs — which were identified by their two-bar spinners — also used gear-toothed mating to the hub adapter. It’s reported that Dayton Wheel owned the patent on this style. Starting in 1964 — when knock-offs were first offered to the public — they used a pin-driven method of mating to the adapter. This makes these early wheels incredibly desirable and rare.
In 1964, the original Kelsey-Hayes wheels had the manufacturing dates ink-stamped on the wheel’s mating surface. For 1965 and 1966, the wheels had the dates hard-stamped on the backside. Then, in 1967, almost as quickly as they appeared, the knock-offs were gone, thanks to federal regulations. The wheels still looked similar, but the rotating spinner was considered unsafe and eliminated.
When To Knock It Off
Many enthusiasts have crouched beside their newly-purchased midyear — hammer in hand — ready to dislodge one of their knock-offs only to find out they were not knock-off wheels. They look like knock-off wheels but are, in fact, bolt-on knock-off wheels. These reproduction wheels were designed to give the stylish appeal of the original knock-offs, but provide the assurance of retaining the wheel using the tried-and-true five-lug fasteners instead of the single spinner.
In this case, the spinner still spins, but only to fasten the chrome cone to the hub assembly. Once the spinner and the cone are removed, the five lug-bolts are easily accessed to remove the wheel. These are great for owners who want the look, but not the burden, of occasionally checking wheels for tightness.
Gettin’ It On
As you can imagine, properly installing something with a hammer is much more important than removing it. Such is the case with knock-off wheels. While there are a few variations, depending on who you ask, there are also some very important, and widely-accepted steps to ensure they remain on the vehicle at speed.
One of the most significant points of interest has to do with the spinners and the hub adapters, not the wheels. The spinners are side-specific. The hub and spinner on the left (driver) side of the vehicle is a right-hand thread, while the spinner and hub on the right (passenger) side are a left-hand thread. The idea is the spinner would only tighten with the wheel’s rotation, not loosen. It’s also debatable whether this is necessary with the modern, aftermarket wheels and their safety pin design. Either way, the aftermarket wheels are also left and right specific.
Once the hub adapters are bolted onto the vehicle’s hubs (ironically, with the five lug nuts), the wheel can be installed, and the trim cone and spinner can be spun into place. There are two different-sized bosses machined into the back of each wheel. The larger holes are there to give clearance for the longer, knock-off-style lug nuts. The other hole is just the right size for a drive pin that will drive the wheel.
If you use regular, short lug nuts, you can unknowingly put the drive pins into the larger lug openings and the lugs into the drive pinholes. This will allow the wheel to rotate on the adapter. Doing so can elongate the drive-pin holes and the wheel could eventually fall off. The larger and longer knock-off lug nuts should prevent this as they shouldn’t fit into the drive pin openings.
Once everything is in place and the car is still in the air, you’ll need a trusty assistant to press on the brake pedal to prevent the wheel from spinning. You want the wheel to freely center itself on the beveled surface of the hub assembly. At this point, you are now ready to take a hammer to your Corvette.
As is the case with any specialized task, there are opinions on the best way to get the desired result. Installing knock-off wheels is no different. Because we’re smacking shiny chrome parts with a hammer, it goes without saying that not any old hammer will do. In fact, Chevrolet provided an approved hammer when you purchased your Corvette or an over-the-counter set of knock-off wheels. A special lead hammer is specified, due to it being softer than the chrome surface of the spinner, and you’ll be hitting it with the hammer – hard.
In today’s modern world, there are new, possibly better, alternatives. Many enthusiasts prefer to use a lead-filled dead-blow hammer. Others opt for a six-pound pounder called the Mother Thumper. This mass of lead has quite a following in the knock-off world and joins all the benefits of a lead hammer with the additional benefits of using a bigger hammer! For those really industrious types, you can even make your own lead hammer, as shown in the video below.
Reportedly, Chevrolet suggested about eight, good whacks with the lead hammer (adjust accordingly if using a Mother Thumper). Then, check to see that the wheel is seated properly. If your wheels have the safety-pin recesses, continue knocking the spinner until one of the pin openings in the spinner lines up with one of the recesses in the hub assembly. Do not install the safety pins at this time. Continue installing each of the wheels in this fashion.
Once all of the wheels are installed, mark a line on each of the spinners and hub adapters and take the car for a short drive around the block. Check to see if each mark is still intact. If not, re-tighten the wheel and re-test. If all spinners appear to be secure, then go for another longer drive, and re-check each spinner. Stop immediately if any wobbling or sloppiness appears, as a wheel may be working itself loose. If everything checks out on the longer drive, then install each of the safety pins and chrome caps.
You’re Never Done
The once-and-done installation of bolt-on wheels is why many Corvette enthusiasts who drive their cars often, opt for the bolt-on style knock-offs. For those who want the full effect of knock-offs — responsibilities and all — diligence is the key to safe travels. Some enthusiasts will safety wire the spinners to ensure that they have not shifted in transport. Others will mark their wheels with tape or other means. The hard-core group of knock-off owners will simply keep their lead hammer handy, and check their wheels from time to time – sometimes mid-trip.
While these wheels are arguably one of the aspects that epitomize the midyear era, their quirks and exclusivity are also one of the things that makes this era’s enthusiasts such a tightly-knit group. Sharing information and know-how with others is a lot easier thanks to the Internet. It might have even simplified installing a set of knock-off wheels, or made them a little safer if nothing else!