Over the past three decades, Mickey Thompson Tires and Wheels has taken a proactive approach in broadening their racing tire lines. They say necessity is the mother of all invention, but we learned an additional adage during our conversation with Senior Product Development Manager, Jason Moulton.
Jason Moulton describes how they explain radial drag tire technology compared to the traditional bias-ply slick: "The bracket radial tire absorbs very little power in the sidewall compared to the standard bias-ply slick. The radial design can be slightly more tricky at the launch, but that sidewall design can be more consistent with less growth at the top end."
“When it comes to some of the things we do in racing, it’s not just from necessity; it’s more about our goals to take new ideas and develop them into improved models or even entirely new tire lines,” Moulton explains. “Several of us, including myself, are drag racers. We are driven by passion for the creation or improvement of every racing tire line.”
Similar to a racer’s quest to go faster, certainly, the racing tire business is a matter of staying on top of that performance. You would not have believed a few years ago that a set of P315/60R-15 ET Street Radial Pro tires with a mere 29.9-inch diameter and 11.4-inches of contact width would propel Mark Micke’s Radial vs. World Malibu to his record of 3.62 elapsed time at 221 mph in the eighth-mile.
What began with a relative handful of ET Drag Slicks in the 1980 has morphed into a product line with 116 different drag tires in the company's extensive catalog and website.
The drag radial line of “sticky Mickeys” may be the poster child of new product development. The concept of radial drag tires started with an idea to benefit Stock Eliminator competition. At the turn of the century, radial racing took a huge upswing with event series such as the NMRA adding radial classes to its lineup. After a few years of establishment, competitive radial classes were exploding in heads-up racing popularity.
In the early 2000s, M/T was looking into developing a DOT drag radial tire line. “The radial has been a big expansion for us,” Moulton remembers. “We started developing our 30.0/9.0R15 radial slick as our first venture. That tire took about a year to develop and eventually it was the tire on the first Stocker to break into the nines. Fast forward to 2018; it is also on Geoff Turk’s Stocker that just dipped into the 7-second zone. All of these years later, that tire is still performing very well.”
It is funny to talk about today, but we were all stunned back in 2003 to see a car on our 275/60 radials break into the 8-second zone. We thought that was amazing then and now look how these radials are performing today. - Jason Moulton
Just one year later in 2004, Mickey Thompson expanded with additional radial tire sizes and saw racers on 315/60-15 tires go deep into the 7-second zone.
Moulton recollects, “It far exceeded our expectations from a performance standpoint. Over the next ten years, the racers took the tire and combined it with the advent of track prep, shocks, torque converters, along with ignition and traction control. They took that tire to the next level, for sure.”
We asked Moulton if there is any collaborative effort between all of the heads-up technology companies like engine tuning and traction control to further the performance levels. He says, “Primarily, it’s really two different efforts. Our focus when we go and test is to achieve a benchmark improvement. We do back to back testing, so it is tire versus tire.”
The small tire that rotated the earth this spring is the Mickey Thompson P315/60R-15 ET Street Radial Pro tires. Mark Micke funneled enough horsepower to the ground to run a 3.623 at 214.79 on a pair of 11.4-inch-wide tires!
Another one of the new product advancements for Mickey Thompson is the development of a new radial tire specifically for bracket racing. Though performance numbers by M/T racers achieve lots of heads-up notoriety, development of the Bracket Radial Tire came from the opportunity to benefit the longtime bracket racing classes.
“Racers ask our representatives for the fundamental difference between bias-ply and radial tires. I sometimes use the variances between the standard bias-ply ET Drag Slick and our newer ET Drag Radial to explain the two fundamental distinctions,” Moulton says. “The bracket radial doesn’t absorb a lot of power in the sidewall. That allows the radial to be quicker and faster. On the contrary, the tricky part about a radial is since it doesn’t absorb a lot of power, it can be slightly more tricky at the launch. What we’ve done for the last eight years is to shorten that gap between the two designs.”
Quicker and faster than their bias-ply counterparts thanks to less rolling resistance and with more consistent roll-out, the Pro Bracket Radial has become a popular choice for sportsman racers looking for a more consistent, reliable, and affordable tire.
Pro Bracket Radial tires from M/T use their reliable X5 rubber compound. The standard ET Drag Slicks use a variety of compounds including the X5.
“The Bracket Radial Tire may be slightly heavier, but it is more consistent. The theory behind the radial tire for bracket racers was to be more consistent while still improving ET over a conventional bias-ply tire. So, consistency, tire life, and value were the goals incorporated into the development of that product,” says Moulton.
“What has made the M/T radial successful in heads-up racing is the ability to put big power to a smaller tire,” Moulton added. “It doesn’t change shape when it goes down the racetrack under huge loads — it stays round. As we look at the bracket radial, the stability of the tire shape offers more consistency down track as well.”
The cords within a bias-ply ply tire are wound at typically a 45-degree angle from bead to bead. The radial tire cords are positioned at 90-degrees to the tire rotation. Moulton further explains how the new technology applies to the drag slick construction.
“It’s not always in how the tire looks when you cut it apart, but also how the tire is manufactured. A bias-ply tire looks like a 55-gallon drum before it goes into the mold. This is very different from a radial tire which is built closer to the final diameter before the molding process. The radial tire does not grow at speed at the top end of the track because they are built closer to the diameter of the mold. That’s because it has a straighter path from bead to bead.”
The Stock Eliminator application was the motivation for the very first M/T Drag Pro Radial. The initial design drove the first stocker into the 9-second zone. Today, Geoff Turk’s “Blackbird” and the same Mickey Thompson radial tire put the first Stock Eliminator entry into the 7’s.
It’s not only about creating new tire designs by Mickey Thompson, but also providing new tire sizes in general for their proven lines such as their ET Drag Slicks. The ET Drag Slick has been offered for drag racing in this fundamental bias-ply design since the mid-1980s. Of course, under constant research and development, the “go-to” drag slick has expanded incrementally over the decades with additional compounds and tire size options.
The E.T. Drag line, including the 32x14 (left), 33.5x16.5 (center), and the 34x13.5.
In the ET Drag Slick line alone, the original 18 various size slicks for the standard 15-inch wheel diameter has grown exponentially. Mickey Thompson currently offers 116 different slick part numbers for 13-inch to 16-inch wheel diameters in a range of seven different compounds. For example; the M/T 29.5/10.5-15 ET Drag Slick is offered in three different part numbers. There is a standard size, another option with an “S” designation for stiffer sidewalls, and a third option sporting a “W” designation which adds an inch to the contact surface width. Each of these choices was developed over the years to fulfill a specific need for different racers.
Two very popular tire lines are the ET Street R and the ET Street Radial Pro tires for the street/strip enthusiast. These are very different tire designs with each catering to the street driven car that occasionally hits the strip, or the more hardcore drag car that uses a streetable tire for racing.
Different rubber compounds are not the only options in tire design offered by Mickey Thompson. Their slicks are available in four different construction options, as well. These range from tires specifically designed for clutch cars to the radial designs, as well as stiff sidewalls for high horsepower and heavier cars, and the extra tread width designs for many class racing applications.
“We try to get quite a bit of information about a customer’s racecar when it comes to recommending tire choices,” Moulton adds. “For racers with a stick shift or clutch applications, it is usually recommended to stick with a bias-ply rather than a radial tire. Because of the sidewall design related to tire shock, radial tires can absorb some shock. However, a radial likes a heavy load applied to it in a constant manner, not shocked.”
The radial tire does not grow at speed at the top end of the track because they are built closer to the diameter of the mold. That’s because it has a straighter path from bead to bead. - Jason Moulton
Referring solely to the drive tire part numbers for drag racing, Mickey Thompson now offers 116 different drive tires using a variety of 12 different compounds. As more drag tires become available, more racers are relying on thorough question and answer sessions with M/T representatives to help them choose their very specific drag slicks.
“If you take our ET Street S/S and our ET Street R, they are both Department of Transportation (DOT) approved tires designed for dragstrip use,” Moulton explains. “Fundamentally, the ET Street R is a DOT-qualified tire with radial pro technology. Compare this to the ET Street S/S which has a steel belted radial design more catered to street use, yet also utilizes the R2 compound for the dragstrip. We will listen to a street/strip enthusiast tell us of his horsepower, drivetrain and how he uses the car before we define a recommended tire. It can be a very fine line between a street car that needs a dragstrip tire, and a drag car with occasional street use.”
Drag Radials get recent "ink" for Mickey Thompson, but they have made big strides in other tire designs. The "Bubba" high growth tires has helped with overpowering or distorting these "big tires" behind big horsepower. Other tires for Junior Dragster and motorcycle drag racing continue to be the leader in their perspective categories.
It’s not just about drag radial racing. The now popular 34.0/13.5-16W high-growth tire named “Bubba” has benefited many big tire classes like Super Comp, Top Dragster and Top Sportsman as a new tire development. One of the characteristics of large tires is severe tire shake caused by over-powering or under-powering the car. The later-developed “Bubba Grande,” a 35.0/15.0-16-inch tire, came from new tire molds and cord designs within the new tire. This extremely popular tire carries high horsepower cars down the track at greater speeds and with less tire shake. These tire designs started over an intense dinner conversation by racers and M/T professionals following a tire development test session.
When it comes to opposites on the drag tire drawing board, Mickey Thompson ET Front tires have a very different design. “Although they are still a bias-ply tire, we design the carcass on these to be light and rigid,” Moulton spells out. “The construction minimizes the footprint from a rounded profile. The goal is a lightweight tire that still provides needed tire speed, wheelstand, and braking durability.”
Mickey Thompson designed their frontrunners with as short of a cord path as possible from bead to bead. Though this sounds like a radial tire theory, it is built on M/T’s bias-ply equipment. The engineering team looked at developing a radial frontrunner, but found it far too expensive to build with no benefits over the current ET Front tires.
Passion to be a leader in the race tire market can be summed up by one of Jason Moulton’s comments: “Our development team is very driven. We go to the racetracks throughout the nation where we will see an opportunity or need. We sit down together at suppertime and start throwing ideas across the table. That is where a lot of our new tire concepts are born.”