By Bobby Kimbrough
Products from Aero Race Wheels, located in Estherville, Iowa, have become a staple at circle tracks across the country. From Saturday night dirt tracks to NASCAR’s highest levels, many race teams use Aero Race Wheels to help them get to the winner’s circle. We talked with Wayne Redmond, one of the big wheels at the wheel manufacturer, and Wayne clued us in on what makes a racing wheel a good wheel.
What Makes A Good Race Wheel?
Several years ago, many wheel manufacturers were using taller bead flanges and oversized bead seats in the construction of their wheels. This required perilously high air pressures to seat the tires on the wheels. In an effort to reduce injuries caused by this, many of the larger racing series like IMCA and Wissota, require additional certification standards by mandating DOT legal bead flanges on the wheels. “Aero Race Wheels makes it’s own dies for forming the wheels that the company offers”, stated Redmond. By making their own wheel forming dies, Aero is able to make wheels that “have a raised tire retaining bead that is DOT legal, but still has an edge to help retain the tire.”
Some of the other certifications specified by sanctioning bodies include additional fatigue testing on the different sections of the wheel to certify for strength. Additionally, some series, IMCA for example, mandates a minimum weight rule of 19 pounds on each wheel to prevent use of lightweight material in the construction of the wheels.
Rolled Or Spun Wheels?
Steel racing wheels can be made by two processes: spun or rolled. Spun wheels are typically stronger than rolled wheels because the material is controlled in tighter tolerances in the spinning method. Flanges, corners and the radii in a spun wheel have consistent material thickness which contributes to the overall strength of the wheel.
There are two basic parts of a wheel: the shell and the center section. The shell is the outer section and is the part that is either rolled or spun in the manufacturing process.
A rolled wheel is made by stretching the material over mandrels or dies. This process causes the corners and radii area of the wheel to be thinner in these areas to conform to the mandrel or die. This is an economical and quicker process than the spinning process and more common in sportsman racing. There has been some studies done that indicate that spun wheels can outlast rolled wheels by as much as 75%.
Most center sections are stamped then spun to create the shape that is needed. The center section has critical areas where the wheel studs are mounted and where the shell is attached. Because these areas must be able to withstand the loading that takes place in these areas, the center sections must be stronger. According to Redmond, “the center section is a very critical point because that is what holds the wheel onto the car, but the actual rim shell is also critical because material that is too light can allow the rim to collapse.”
For most Bomber Stock and Modified racing classes, usually conducted on 1/4 mile to 1/2 mile tracks, the rolled wheels will handle the stress of side forces created under these conditions with no problem. Drivers on tracks with higher speeds and tighter corners may benefit from spun wheels.
- Bolt pattern or lug pattern or bolt circle: Determined by the number of bolt holes and the bolt circle diameter.
- Hub Diameter or center bore: The hole at the center of the wheel.
- Rear spacing or back spacing: The distance from the backside of the wheel mounting pad to the outside of the rim flange.
- Offset: The distance from the centerline of the wheel to the mounting surface of the wheel.
- Negative offset: When the back of the bolt pad is closer to the inside of the wheel; when mounting surface is inboard of the rim centerline.
- Positive offset: When the back of the bolt pad is closer to the street side of the wheel; when the mounting surface is outboard of the rim centerline.
Wheel Maintenance
Wheels should be visually inspected each week or after every race. Look for dents, bent rims and cracks. The area where cracks are most likely to be found is the weld area where the center section is welded to the shell. Welding the crack or replacing the wheel are the only options when you find a crack. Continuing to race on a wheel that has a crack is a recipe for disaster. Cracks will grow rapidly as they are subjected to the side loads of racing.
The lug nut holes should be inspected weekly to ensure that the holes have not become enlarged or elongated. A tell-tell sign will be in the tapered seat area of the hole. If the tapered seat is not smooth and round, then you likely have wear in lug nut hole.
Check the lateral wheel run-out, often referred to as “wobble”, at least three times a season. Using a dial indicator to measure the run-out, check that the wobble is no greater than 0.030”.
Check the condition of the bead flange. Some dents can be straightened out in this area, but keep in mind that if you bend this flange often, the metal becomes weaker. Redmond explained by saying; “Successfully straightening out the flange depends on the grade of material used by the manufacturer. Some material may be brittle and will crack when bent. We actually designed a wrench that bends flanges back into shape and we market it with confidence because the material in our wheels can withstand the use of this tool. It’s not designed to bend the flange after every race though. It’s a one shot deal then you probably need to replace the wheel.”
Proper Lug Nut Torque
Lug Size Ft/Lbs Torque
7/16″ 55-65
1/2″ 75-85
9/16″ 95-115
5/8″ 135-145
12mm 72-80
14mm 85-95
When In Doubt…ASK.
Our final word on selecting, inspecting and maintaining your race wheels is, if you have doubts, call the manufacturer and ask.
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