Rare is it that we're talking about 14-inch rims and skinny tires here at MM&F. More often than not, the feature cars you see on these pages are running some serious performance rubber on at least a 16-inch rim, if not a 17- or even 18-inch rim, and why not? If you're building a classic Mustang or Ford with better handling and braking that puts out more power, you truly need a better performing tire that has more grip for better traction, shorter braking, and improved handling. A larger contact patch and shorter sidewall all work together to enhance these attributes in a classic Mustang or Ford. Of course, these modern radials try to do everything better, but if you're more of a track junkie and all you want to do is go fast in a straight line, then usually a specialty tire is more in line with your needs.
When drag racers hit the tracks back in the '50s and '60s, there weren't any radial tires to begin with, but there were slick tires. Slicks were tires completely devoid of any tread pattern for the optimum in straight line traction and contact patch. Their sidewalls were soft, allowing the tires to bite into the pavement. Eventually, we saw the development of the DOT (Department of Transportation)-approved bias-ply drag/street tire, which had just enough tread on it to be street legal in the DOT's eyes, but was made from a soft compound rubber and did its best to act like a slick in the traction department. Both of these tire technologies have had a long and fruitful life. So much so that they're still available and used widely today on a full range of carsùfrom classic Mustangs to street rods and hot rods.
The latest drag tire technology to reach the track surface is the drag radial. Found as either a full slick or with a DOT tread, the drag radial offers a high traction rubber compound wrapped around a standard radial tire carcass. The radial allows for heavier loads, and can be more stable at speed, something that makes many racers feel more "comfortable" at the big end.
So what's the right tire for your ride? Only you can ultimately decide what tire best suits your purpose, vehicle, horsepower, and other factors, but we've reached out to the best in the tire business to help you answer those questions and fit your ride with the right rubber. Check out the following captions and see what bias-ply versus radial drag tires can do for your e.t. the next time you hit the quarter-mile.
Drag Tires: Bias-ply versus Radial
We spoke with several tire company engineers and when we asked them about bias-ply and radial construction drag tires they all agreed that it comes down to tire construction and compound.
Tom Kundrik of Mickey Thompson tires tells us radial tires, as compared to bias-ply tires, absorb more energy. "Why is that?" we asked. Well, it starts with the way the components of the tire are assembled. In a bias tire, the tread and sidewalls share the same plies, causing the sidewall to flex. This flex can be transmitted to the tread, causing deformation of the contact patch. This construction creates more friction with the ground, which is a good characteristic for a "drag tire," but in some cases can be parasitic. With radial construction, the sidewall plies run across the tire and the tread plies, also known as "breakers," run in a longitudinal manner. This construction technique produces a flat, stable and wider footprint on the ground. The radial has less distortion of the contact patch surface and better ground pressure distribution.
We gained further construction details when we spoke with Eric Gullett of Coker tire, who manufactures M&H tires and Phoenix drag tires.