Jamis Decon 1 Test

Jamis Decon 1

Lock and Loaded

jamis-1The word DEFCON refers to the defense readiness condition of the armed forces. Get it? “DEF” (defense) “CON” (conditions). There are five different levels of DEFCON, numbered from one to five, with one being the most urgent. A DEFCON Level 1 situation means the United States is anticipating imminent war, which requires a maximum level of readiness and a finger on the big red button to launch the nuclear warheads. So, when Jamis decided to name its new enduro rig the Defcon 1, Jamis must have been certain it was ready for action. We brought one of these bikes to our favorite enduro-type trails to put it to the test and see if it could really “turn the keys” and declare war on the trails.


jamis-10Boostin’ it: Our most aggressive test riders found the limits of the Defcon when hitting trail features, as they were able to bottom the bike out. However, with some tweaks to the stock suspension setup, this would likely be a non-issue.

The Defcon is an enduro bike with enough travel to handle the gnarliest of trails. The slack geometry and plush suspension are built to ride fast and take chances on technical terrain. It’s also built light enough to handle climbs to earn those descents. Make no mistake; this is a high-end machine; however, Jamis does an excellent job building value into its bikes, so the Defcon is an excellent choice for any aspiring enduro racer who doesn’t have an energy-drink sponsor but still wants to stand on the podium. Oh yeah, we forgot to mention it makes a heck of a great trailbike too.


Clean internals: The Defcon works with nearly any derailleur setup with internal routing in key places to keep the looks clean. Should you not need to use any of the ports, the bike comes with these nifty caps to make it look streamlined.

jamis-5One burly piece: The Defcon’s rocker delivers 160 millimeters of travel. Thanks to its one-piece construction, the bike sports more stiffness than it would if this piece was kept spindly and minimal.

jamis-3MP4 linkage: Jamis designed their MP4 suspension system with a “faux bar” system, which is essentially a tried-and- true design that uses a single main pivot and a rocker to drive the shock.

The Defcon is an aluminum bike built with 160 millimeters of travel via the Jamis MP4 suspension design. It’s a single-pivot design that uses a rocker and swingarm setup to optimize the linkage and provide a supple but progressive spring curve. That’s fancy talk for “it works on the small stuff but doesn’t bottom out on the big hits.” The bike rides on high-end Enduro cartridge bearings throughout, which are designed for longevity. The Defcon sports a very modern geometry that’s capable of handling the toughest enduro runs or the most technical trails—short of a World Cup DH course. The bike comes in several versions, all of which deliver great bang for the buck on components. Our top-end Defcon 1 also comes with a 142-millimeter rear axle, tapered head tube, 10-millimeter oversized suspension hardware and mounts for any type of derailleur you want to ride with.


jamis-4Modern but compatible amenities: The Defcon 1 comes to the table with post-mount brake tabs, thru-axles front and rear and a threaded bottom bracket. The bike is all about delivering performance without complicating the system too much.

jamis-8Nice touch: The KS post comes with the fancy, under-the-bar Southpaw mount right from the factory. Any single-ring rider will appreciate this additional feature.

The Defcon 1 is the top-end offering but still delivers value with a group set that’s well thought out and ready to hit the trails right out of the box. The Shimano XT build kit comes with a single-ring drivetrain that no rider will feel the need to upgrade. The bike also comes with top-end Fox Factory suspension, including a Float 36 fork and Float X Evol shock. Again, there is no need for any component swaps out of the box. Whether you plan to ride, race or rally this machine, it’s ready to rumble.


Moving Out:

The Defcon is low, slack and modern. It fits like a quick and racy enduro bike with a relatively long front center, low bottom bracket and geometry that’s built to slay the gnarliest trails. It’s not the lightest bike at this price but could be put on a diet to be pressed into race shape.

jamis-11Uphill battle: The Defcon was designed to plow down descents with enough climbing prowess to also float uphill without a shuttle. While not the bike’s first purpose, our riders were impressed with this bike’s ability to climb, both on smooth grinders and technical ascents.


This is a plush bike first and foremost, so the pedaling efficiency must rely on the suspension dampers to provide a platform for efficient pedaling and climbing. Fortunately, the levers on the fork and shock are very easy to use and limit the amount of suspension bob to keep the bike feeling quick and efficient when pointed uphill. The Defcon carries its weight up the hill well as long as those suspension switches are used.


The Defcon delivers stable and confidence-inspiring handling, especially on fast and rough trails. The bike is particularly plush and delivers enough high-speed bump compliance to keep the bike under control even when the speeds are high. The wheelbase and chainstays are also relatively short, which makes the slow-speed handling through switchbacks, whether uphill or down, more than manageable.

jamis-9Shred-ready: This bike is plush, there’s no doubt about it. The Defcon handles rock gardens with ease, and delivers confidence that the suspension and frame will eat up any mistake the pilot may make.


This is where the Defcon shined. The 160 millimeters of travel delivered a nice balance of small-bump compliance and big-hit control that handled everything we could throw at it. The bike’s air-sprung suspension combines with the single-pivot design to provide a feel that’s somewhat bottomless. Despite the fact that this is not a true downhill or freeride bike, this thing could pull daily duty as a bike-park bike with confidence.


The build kit leaves almost nothing to be desired, so the upgrades are up to the rider’s personal preference. Simply put, there is no part on this bike we wouldn’t ride ourselves. You can swap all you like, but for the price, you’re not going to do much better than what you find on the Defcon.

The only thing this bike doesn’t come with is a tubeless-tire setup, since all-new bikes must come with tubes installed to be legal. Thankfully, the bike has Stan’s NoTubes rims that are pre- taped and Vittoria tires that are tubeless ready. We recommend converting to tubeless before your first ride and keeping the two stock tubes as spares in the unlikely event you have a puncture your sealant can’t handle.



The Defcon 1 would be as comfortable on an aggressive all-mountain ride as it would be on an enduro racecourse. The bike has dialed suspension that’s controlled throughout the travel and handles small bumps and big hits exceptionally well thanks to the progressive MP4 design. While not the lightest bike we’ve tested, the bike proved its mettle with a combination of handling, durability and dialed geometry that could handle any trail we threw at it. The Jamis Defcon 1 is a great value, but to say that this is a bike that will only appeal to riders on a budget would be wrong. This is a bike that a rider can grow with, one that ticks all the most important boxes and will be in it for the long haul.



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