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
TRICKS, UPGRADES OR TIPS?
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. For tips on which sealant to use,
check out our shootout on page 32.
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 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.
Cornering: 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.
Descending: This is where the Defcon shined. The 160
millimeters of travel delivered a nice balance of small-bump
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.
Boostin’ 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.
MP4 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.