Finding something of serious newsworthy value at Interbike 2015 isn’t an easy task – after all, EUROBIKE has been stealing the thunder from the stateside trade fair for years. However, upon laying eyes on the brand new JAMIS Defcon I in the furnace of Nevada’s desert, we think we might have nailed it, as the US cult brand present their first 160 mm enduro bike for the hardcore rider.

Tradition is all well and good, but innovations are even better. As one of the oldest American bike pioneers, the Florida-based Jamis were already creating beach cruisers as early as the end of the 70s, which rapidly evolved into a modified off-road cruiser – essentially, some of the first mountain bikes.


Jamis Defcon I: The cult American brand’s first 160mm enduro bike makes a solid first impression.

The brand new Defcon I has very little in common with the relics of bike history when it comes to its look and its technology. In inferno red, the aggressive-looking 27.5″ machine has a modern design. A long front end, short chainstays and a solid aluminium frame make it look more than ready to do battle.


Jamis kept to their ‘mp4’ rear end design for the Defcon I, retaining the asymmetrical chainstays and the Kashima coated FOX Float X EVOL rear shock.

The Defcon I appears to have ‘always prepared’ as its motto, and if you’re not a fan of getting your hands dirty and digging out the tools, then the low-maintenance Jamis could be one for you. Eliminating a seat-stay bridge, the rocker arm design has allowed Jamis to create shorter chainstays and more tire clearance. Moreover, the 160 mm bike comes kitted out with wide and up to 40% more stable MAX ‘Enduro’ bearings to increase lateral and torsional rigidity.


Low-maintenance “Enduro” headset bearings from the US company MAX and internally routed cables in the headtube area.

Frustrating for mechanics, but a treat for the owner, the custom 10 mm shock hardware should guarantee less stress for the shock and a longer lifespan. According to Jamis, the ‘mp4’ rear end results in a progressive spring curve, responsiveness in the low to mid-travel range as well as minimal risk of bottoming out. Naturally, any pedaling is purported to be as efficient as possible. Could the Defcon I represent what we’re all after: ‘One bike to rule ‘em all.’


The Shimano Saint ICE-Tech 4 caliper disc brakes should adequately bring the Jamis Defcon I to a halt.

Given that it’s a modern enduro bike, the geometry is fairly standard: with a 66.5˚ head angle and 73.5˚ seat angle, Jamis are bridging the gap between an all-mountain climber and a fun-loving enduro whip. In fact, Jamis claim the Defcon I is clearly orientated towards adrenaline-fuelled riders taking direct lines, big jumps and more speed, leading to a blurring of the lines between aggressive trail bike and bomb-proof weapon for the bike park.


Die Shimano Saint ICE-Tech 4-Kolben-Bremsanlage soll das Jamis Defcon 1 fein dosierbar zum Stehen bringen.

Housing some high quality pieces of kit, the top of the range Defcon I features FOX 36 Float forks at the front and the perfectly harmonizing Kashima-coated FOX Float X EVOL Factory rear shock. The suspension set-up is a cert for keeping the tyres planted on tough terrain, as well as helping it to handle like a precision machine. The Shimano Saint brakes take care of well modulated anchoring.


Shimano XT 11-speed drivetrain: thanks to the optional chain guide mount, you can upgrade the Defcon I as you see fit.

Jamis have clearly given reliability a great deal of thought, opting for tried and tested Shimano XT components and a groupset that speaks for itself: stiff cranks, low weight and impressive shifting even under load are in genes of this Shimano set. With the LOADED Precision X-Lite tubeless wheelset, Jamis selected one of the smaller but no less skilled American manufacturers, who are riding a wave of success in the US for their craftsmanship. The well-equipped trail weapon is rounded off with a KindShock dropper post with internal cable routing and an ISCG05 chain guide mount.


Kindshock LEV DX dropper post with an internally routed cable and a wisely positioned trigger.


Loaded Precision X-Lite X30 27.5” tubeless wheelset with a 15 mm thru axle at the front and 12×142 mm rear thru axle.

Clearly JAMIS haven’t designed a bike for weight-conscious enduro racers. Weighing in at 14 kg, the market has seen many more lightweight models. But weight was never the key feature of the Defcon I, as the Americans set about developing a bike that wouldn’t leave anything to chance on the trails.


Loaded cockpit components in an eye-catching anodized blue give the bike a stylishly aggressive look.

Having fallen for the fiery red whip, we are now waiting impatiently for a Defcon I to put on long-term test. If the 4,900$ top of the range model is out of budget, the Defcon II, which retails around 3,800$, is a sweet back up, featuring RockShox suspension, a SRAM drivetrain and the identical wheelset.

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Text & Photos: Steffen Gronegger

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About the author

Aaron Steinke

Aaron was our first employee and actively helped make our company what it is today, significantly shaping the look and direction of our various magazines. Aaron has been pursuing his own projects since mid-2020 but he continues to advise and support us on issues of marketing and technology. For many years, you would usually have found Aaron at casual enduro races, but increasingly you'll find him riding his road bike – long live freedom on two wheels!