Dunlops New Geomax MX Tire Lineup For 2009!

The New Dunlop Geomax Tires Are Really Sick Stickers Baby!

Dunlop recently introduced the successor to their tried-and-true Dunlop D756 tire, which is no small feat. It was Dunlops best-selling motocross tire, and enjoyed a large and loyal fan base among riders. The new MX51 is the replacement for the D756. Designed as an intermediate tire, one of Dunlops primary goals was to stretch the performance capabilities even further into the hardpack and soft terrain conditions, while also boosting durability. The other big hitter in the Geomax line is the MX31, which replaces the D773, and is designed to excel in sand and mud conditions.
Carcasses on both the MX51 and MX31 are stiffer than previous designs. While talking with Dunlops Broc Glover, we asked how much the four-strokes had influenced the design of the new tires. He explained, Thats basically when we started to develop this tire. I have to say it was primarily built around the 250Fs and 450s. We were the first to build a tire specifically for the 450s, but they were probably15-20 pounds heavier than the bikes are now. Now the bikes are much closer to what the typical two-stroke weights were. The old tire was designed more for when you let off the throttle of the 450, the particular extra load was put on the front tire, so the carcass needed to be a lot stiffer. Ironically, at the pro level we ran that stiffer carcass on almost everybodys bikes, because those riders like to run ten to eleven psi, but they were also going faster and putting more load on the tire than the average motocross rider would be. We did learn a lot with the four-strokes.

Obviously Andrew Short has a lot of experience with the MX51, having spent quite a while working with Dunlop on the development.

Varying the angle of the different tire plys in the carcass can affect its stiffness, and Dunlop used their experience with their racing efforts to develop the stiffness that they were looking for. It provides a very stable platform that can handle lower tire pressures, which gives you a larger footprint, but without losing its stability and rolling over or deflecting too much as you hit obstacles.
The new carcass also tracks well, which is something that Andrew Short noted. For me its always felt really good when youre on the sidewall accelerating and turning, like a faster sweeper. This one seems really consistent, and doesnt have any of that wallow feel to it.
As for the tread pattern, the MX51 uses an all-new pattern that Dunlop calls the Geomax Reinforced Pattern. Youll find a more widely spaced center area than the 756, and the tread shifted to the shoulders of the tire for added cornering grip.

The rear tire has plenty of recessed biting edges on the outer knobs, a more open center section, and tie-bars that help connect and reinforce the tread blocks.

On the front tire, youll find more recessed biting edgesthe dimpled area in the center of each knob. These same recessed areas are found in the outer blocks on the MX51 rear tire. To boost the strength of the knobs, they have large radiuses where they meet the carcass, and they also use a tie-bar to connect and reinforce the tread blocks. That adds strength and toughness to the knobs. Between the tread blocks youll see recessed areas that add extra compliance for bump absorption.
Oh, and the first wins for this tire? Trey Canard was using a version of it last season en route to the Supercross Lites East title, and Kevin Windham scored the first 450 win on it at Seattle.
To check out more, you can click into the photo galleries of the new Dunlop MX51 and MX31 tires (see above), and check out the Vital MX Perspective, where we talk to Honda Red Bull Racings Andrew Short, and Dunlops Broc Glover about the new tires. And finally, below you can find all the new sizes available.

Dunlop MX5 and MX31 Sizes and availability
The MX51 and MX31 will be available in the following sizes at Dunlop dealers beginning in February, 2009.
MX51
Size
Load/Speed
POSITION
2.50-10
33J
FRONT
2.50-12
39J
FRONT
60/100-14
30M
FRONT
70/100-17
40M
FRONT
70/100-19
42M
FRONT
80/100-21
51M
FRONT
90/100-21
57M
FRONT
2.75-10
38J
REAR
80/100-12
41M
REAR
90/100-14
49M
REAR
90/100-16
52M
REAR
110/90-18
61M
REAR
120/90-18
65M
REAR
100/100-18
59M
REAR
110/100-18
64M
REAR
100/90-19
57M
REAR
110/80-19
59M
REAR
110/90-19
62M
REAR
120/80-19
63M
REAR
MX31
Size
Load/Speed
POSITION
2.50-10
33J
FRONT
2.50-12
39J
FRONT
60/100-14
30M
FRONT
70/100-17
40M
FRONT
70/100-19
42M
FRONT
80/100-21
51M
FRONT
2.75-10
38J
REAR
80/100-12
41M
REAR
90/100-14
49M
REAR
90/100-16
52M
REAR
110/90-18
61M
REAR
120/90-18
65M
REAR
110/80-19
59M
REAR
120/80-19
63M
REAR