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Rock Shox introduced Motion Control damping
in 2004, the simple design utilizes a relatively basic
orifice-type damper plus a supplementary blowoff valve, but careful
execution of the design delivered extremely competent bump performance
that was also very user-friendly. In spite of criticisms that the design
used too much plastic (in fact, the design relied on the flexable
material), the system has proven to be impressively durable.
However, Motion Control is not the most efficient
of compression damper designs. In  particular,
long-travel (these days considered to be roughly 120mm+) single-crown
forks present among the most challenging conditions for a damper to
handle, and it is in these unique applications that Motion Control is not
ideally suited. Those forks arguably witness the widest range of usage
conditions, from pedestrian trailbike to aggressive all-mountain/freeride
applications. These forks are often just as likely to be ridden uphill in
addition to down, and must make concessions to pedaling efficiency and
light weight without sacrificing bump performance.
At the higher damper shaft speeds and more aggressive
applications that are often associated with longer travel, the
simple-yet-effective architecture of Motion Control essentially has a
little too much to deal with. As such, since its introduction, Rock Shox
has only utilized it in short-to-mid travel platforms, with the exception
of the Boxxer which uses a modified "Speed Stack" version.
Not surprisingly, suspension companies across the board
have tended to pack their most advanced technologies into the long-travel
single crown categories, but it is in exactly this segment that Rock Shox
has often struggled in the past (anyone remember the Psylo?). Knowing the
uphill battle it faced, Rock Shox knew that it would be given little
leeway, if any, as it attempted to re-enter the fight with its new Lyrik
and Totem lines.
Rock Shox took the lessons learned from Motion
Control to develop a wholly new damper specifically designed for these
applications. The new damper, dubbed Mission
Control, is the first from Rock Shox to offer
completely separate, and fully-tunable, low-speed and high-speed
compression damping circuits. Low-speed inputs are still handled by a  simple orifice-type design that incorporates an adjustable port,
similar to most other designs currently on the market. High-speed inputs,
however, are now handled by a dedicated shim stack, located just atop the
main piston body. Under more extreme conditions, this additional circuit
delivers more carefully controlled oil flow for better control.
User-tunability is provided by the cleverly-integrated adjustable spring
preload on the stack.
Both of these circuits are supplemented by a downsized
version of Rock Shox' Floodgate platform valve design. Unlike the large
red 'spring tube' layout of the Motion Control damper, Mission Control
incorporates a dramatically downsized version that utilizes the company's
new Isolite material to deliver largely the same functionality. As with
the original Motion Control, the Floodgate platform threshold is
externally adjustable. A simple crown-mounted switch toggles the platform
feature on and off in this case, but in either setting, both the low-speed
and high-speed circuits remain fully functional when the fork is
active.
This wealth of adjustment means that the new damper design
should offer a suitably wide range of adjustment for a correspondingly
wide range of conditions. At the same time, however, many users may be
intimidated by the potential for getting things wrong. Thankfully, all of
the compression damper adjustments are located atop the crown, and are
also detented for easy recording of settings. Moreover, Rock Shox also has
a setup guide in the works for easier deciphering of
adjustments.
James Huang
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