All-new Dunlop Geomax MX71 Tires 3

Dunlop has added a third set of next-generation tires to their Geomax lineup, the MX71s, which are designed specifically for hard-pack and blue-groove conditions. This follows the MX51 (intermediate), and MX31 (soft terrain). Here’s the scoop from Dunlop.

Dunlop MX71 front. Click image for a larger version.

The introduction of the Dunlop Geomax™ MX71 tire, which is designed to deliver optimum performance in hard-pack riding conditions, is the latest in the line of next-generation motocross tires released by Dunlop in the past year. Following on the heels of the intermediate-terrain MX51 and the soft-terrain MX31, the MX71 combines Geomax proven carcass construction and compounding with state-of-the-art tread design to deliver enhanced performance in hard-pack/blue-groove conditions.

Dunlop MX71 rear. Click image for a larger version.

Carcass Construction

The successor to the popular D745 and D739, the Geomax MX71 employs the same carcass construction first unveiled in the D756RR racing tire, and successfully introduced in the MX51 and MX31. Modern-day four-stroke Supercross and Motocross machines place great demands on tires, and competitors utilize riding styles that emphasize the need for immediate traction and durability without sacrificing handling. These demands are especially apparent in Supercross, where hammering through hard-packed whoops, railing through berms, nailing jump faces and landing off jumps is the norm.

In these conditions, lower tire pressures can yield a larger footprint for added traction and help moderate the jarring forces transmitted to the suspension and the rider. To reap the benefits of lower tire pressures while also maintaining optimum handling, the MX71’s carcass is significantly stiffer than previous-generation hard-terrain tires. This was accomplished by incorporating a ply of high-density polyester cord engineered at angles derived from prototype racing tires developed by Dunlop-supported factory racing teams. The resulting reinforced carcass provides a more stable platform that eliminates the loose feel often associated with lower tire pressures. Dunlop test riders confirmed that the new construction tracked better, held a line more easily through fast sweeping corners with less rebound over bumps and whoops, all of which increased rider confidence.

GRP Tread Design and Advanced Compounding

Once Dunlop had engineered the tough, durable Geomax carcass, it became the foundation for the application of the company’s latest tread design and compounding know-how. Extensive modeling using three-dimensional FEM (finite element modeling) and FEA (finite element analysis) resulted in the creation of a series of prototypes tested extensively at Dunlop’s Huntsville Proving Grounds and throughout the 2008-09 AMA Pro Racing Supercross and Motocross series by Dunlop’s professional racers. The resulting patterns for the Geomax family of tires were branded GRP™, or Geomax Reinforced Pattern™.

Dunlop’s GRP tread profile enhances performance and tread durability, a result of Dunlop’s use of proprietary compounding technology that employs ultra-fine, long-life carbon black. The resulting tread produces consistently high grip over a broad range of operating temperatures and surface conditions.

Use of this compounding technology allowed Dunlop engineers the freedom to “open up” the center-tread area of the GRP design for a greater land/sea ratio. This results in the tread blocks dynamically digging in for enhanced traction, rather than floating or spinning on the looser top surface. The benefit is improved straight-line acceleration and braking performance. Similarly, more tread volume in the shoulder area yields high grip and enhanced handling and bump absorption.

The directional front tire incorporates a GEOmetric block shape on the shoulder knobs along with cross-stitched block placement for enhanced cornering traction and braking grip, and more predictable slide control. The directional and asymmetric rear tire pattern Dunlop calls the “Double Tornado Wave” is an exclusive tread block distribution which produces enhanced grip at various lean angles. The unique placement of “camber traction knobs” provides enhanced forward traction at various lean angles when exiting corners and makes it easier to cross over ruts when tracks get rough. Both the front and rear tire tread blocks have a large base radius for increased strength, and toughness is enhanced by a tie-bar that connects and reinforces the tread blocks to enhance wear resistance.

Every tread block on the front tire and each shoulder block on the rear tire features recessed biting edges which yield more traction for greater grip throughout a wide range of terrain conditions.

Real World Performance

With 105 national championships in the dirt, Dunlop knows about competition. And there can be no product-testing crucible more demanding than the arena of professional AMA Supercross and Motocross racing. Dunlop’s Geomax designs--consisting of the hard-pack MX71, the intermediate-terrain MX51, and the soft-terrain MX31--were developed with the assistance of some of the world’s most demanding riders, including Honda Red Bull Racing’s Andrew Short and Davi Millsaps, and Geico Honda’s Kevin Windham and his 2008 Supercross Lites East champion teammate Trey Canard. From their evaluations emerged the most significant line of Dunlop motocross tires in a decade. As a result, many more top-level AMA riders have joined the Dunlop Geomax ranks for 2009 and 2010, from disciplines ranging from high-flying Supercross and Motocross, to scorching Baja desert racing, to national-champion mini riders. Now, with the release of the Geomax MX71 in mid-2010, every weekend warrior can ride on the same rubber as his or her riding heroes.

Wide-sized Benefits

- Dunlop innovation developed to harness and transmit power to the ground.

- Provides a larger footprint for enhanced traction and improved bump absorption.

- Fits on standard-sized rims.

Conversion Chart

80/100-21 - 90/100-21

100/90-19 - 110/80-19

100/100-18 - 110/90-18

110/90-19 - 120/80-19

110/100-18 - 120/90-18

Geomax Reinforced Pattern

Dunlop‘s Geomax tires incorporate knobs placed in a unique shoulder block distribution for enhanced traction and tenacious grip across a wide range of riding conditions.

Geomax MX71 Sizes

Size - Load/Speed - POSITION

70/100-17 - 40M - FRONT

70/100-19 - 42M - FRONT

80/100-21 - 51M - FRONT

90/100-21 - 57M - FRONT

90/100-14 - 49M - REAR

90/100-16 - 52M - REAR

110/90-18 - 61M - REAR

120/90-18 - 65M - REAR

100/90-19 - 57M - REAR

110/80-19 - 59M - REAR

110/90-19 - 62M - REAR

120/80-19 - 63M - REAR