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Mickey Thompson Deegan 38 Tire Test

Posted in Product Reviews on March 19, 2015
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If you’ve spent any time at all following the early days of the freestyle motocross (FMX) world, then the name Brian Deegan rings a bell. He was well known for his anti-establishment antics, following his own rules, and doing his own thing. Unfortunately, we all have to grow up, and being an outcast rebel doesn’t pay the bills. As younger, faster, and more talented riders moved up the ranks, Brian Deegan reinvented himself and morphed into becoming a successful short-course off-road race driver. That eventually connected him with Mickey Thompson. The relationship eventually led to the development of the Deegan 38, an aggressive, made-in-the-USA, radial mud tire designed to work well both on- and off-road.

Don’t be fooled by the Deegan 38 insignia. The 38 refers to Deegan’s race number, not the tire’s diameter. The Deegan 38 is currently available in 13 different sizes for 15, 16, 17, 18, and 20-inch wheels. The smallest tire available is a 31x10.50R15, with the largest being a 37x12.50R20. We settled into a quartet of 37x12.50R17 tires. The first thing we noticed about the Deegan 38 is its light weight, especially when you consider that our 37s have a D load range and are capable of supporting 3,525 pounds each at 50 psi. A lighter tire will outperform heavier tires in terms of braking and acceleration. That should always be a consideration when installing larger tires.

The chunky tread lugs are best suited for mud and other loamy off-road terrain. The sipes in each lug will help in wet weather and winter conditions, although we would choose a less aggressive tire for regular ice runs.

We mounted our Deegan 38s on 17x9 Mickey Thompson Classic Baja Lock aluminum wheels. The simulated beadlock wheels are sprayed with a matte-black protective finish. Each ring is machined into the wheel. Because it’s not removable, it adds strength to the outer edge of the wheel to help avoid damage in the rocks. The Classic Baja Lock wheel is great for those that like the look of a real beadlock without the complexity, expense, or potential street-legality issues. They are available in 15, 16, and 17-inch diameters, in widths from 7 to 12 inches wide.

Our Deegan 38 tires required very little weight to balance out—Each of the four tires needed less than 2 ounces to spin true. On the street, you should expect some road noise, as they are not all-terrain tires. However, the tighter inner void sections of the tread help to reduce overall noise.

The Mickey Thompson Classic Baja Lock aluminum wheels feature a built-in (not removable) simulated beadlock ring that makes the wheel stronger and less susceptible to damage from hard hits off-road. The matte-black finish and smooth wheel design make it easy to clean.

The large aggressive tread lugs make the Deegan 38 a good choice for mud and other loose and loamy terrain. The chunky lugs have sipes, which helps with wet and ice covered roads, but if ice sheets are a regular staple for your 4x4, you’ll probably be better off with a less aggressive tire that has more siping, like the Mickey Thompson Baja STZ. Even at street pressures, the Deegan 38 tread and sidewalls flex and envelop rocks and other obstacles, thanks in part to the sipes in the lugs. Airing the tires down to the low teens is ideal for most trails without the use of true beadlock wheels. The large outer voids allow the Deegan 38 to self-clean in the sticky stuff.

The light overall weight, easy-to-balance characteristics, and load capacity make the Deegan 38 a good option for heavy-duty tow rigs, as well as smaller 4x4s. The two-ply sidewall of the Deegan 38 is definitely sturdier than a run-of-the-mill radial tire. However, we would probably want a little more beef if we planned to frequent off-road areas with an excessive amount of sharp split granite. Brian Deegan supporters will appreciate the raised white Deegan 38 lettering available on all but the 20-inch sizes. We opted to put the white letters in. Regardless of if you like and follow Brian Deegan or if you’ve never heard of him, the Mickey Thompson Deegan 38 is a solid on- and off-road tire you can depend on.

Even at street pressure, the tread and sidewall of the Deegan 38 envelops obstacles. Most off-road conditions can be handled with air pressures set in the low teens.

Tire: Mickey Thompson Deegan 38
Size: 37x12.50R17
Type: Radial
Load range: D
Max load (lbs): 3,525
Sidewall construction: Two-ply polyester
Tread construction: One-ply nylon, two-ply steel, two-ply polyester
Approved rim width (in): 8.5-11
Tread depth (in): 21⁄32
Tread width (in): 9.88
Section width (in): 13.1
Overall diameter (in): 36.7
Maximum psi: 50
Weight (lbs): 73


Mickey Thompson Performance Tires & Wheels
Stow, OH 44224

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