It no secret that the 2017 CRF450 has
suspension issues, both front and rear. Many of
these can be alleviated by stiffer fork and
shock springs, but springs don’t address
the seat height, chassis setup or wallowing
problems. The Pro Circuit link does.
PRO CIRCUIT 2017 HONDA CRF450 LINKS
MXA TEAM TESTED
WHAT IS IT? Pro Circuit’s 2017 Honda CRF450 linkage
not only lowers the tall rear of the CRF450, it also stiffens
the initial part of the shock’s stroke for better control and
less wallowing in the rough.
WHAT’S IT COST? $224.95.
CONTACT? www.procircuit.com or (951) 738-8050.
WHAT STANDS OUT? Here’s a list of things that stand
out with the Pro Circuit 2017 Honda CRF450 shock links.
(1) Purpose. A longer shock link can alter a bike’s rising rate, kick out the head angle and lower the seat height.
Since the 2017 Honda CRF450 has a stinkbug stance and
tends to wallow in the initial part of the stroke, a lower
shock link can address these issues. The Pro Circuit 2017
Honda CRF450 link arms are 1.5mm longer than the stock
144mm link arms. The Pro Circuit link lowers the rear of
the bike by 12mm.
( 2) Linkage theory. Shock linkages work by compressing the shock from the bottom while it is being compressed against the top shock mount by the energy of the
bump. By altering the speed of the shock per millimeter of
stroke, damping is increased as the shock moves upward.
How it does this is very simple. Since the orifices in the
shock piston are fixed, they flow more shock fluid at low
speeds than they can at high speeds. As the shock shaft
speed increases, the fluid can’t get through the orifices
as fast, thus the flow rate is impeded, much like trying
to push a 10-pound pig through a 5-inch hole in a fence.
The harder you push, the slower the pig goes. In action,
changes in the speed per millimeter allow for a softer feel
in the first one-third of travel, progressively stiffer damping
in the middle third, and supreme bottoming resistance in
the final one-third of the stroke.
( 3) Rising rate. The speeding up of the shock as it
moves upward is called rising rate. It is common prac-
tice for the manufacturers to change the rising rate to
solve suspension issues. For example, if a bike bottoms
excessively over big jumps, the engineers will make the
shock resist bottoming by making the shock move faster
in the final third of the stroke. Conversely, if a shock is
too stiff at the end of its stroke, the engineers will go to
a less progressive rate change to make the suspension
( 4) Linkage arms. It is important to note that ris-ing-rate changes are achieved by the eccentric cam of the
shock linkage’s bell crank, not the linkage arms. Longer
link arms do not change the rising rate. Instead, they
change the starting point of the shock on the existing
leverage curve. The longer arm achieves this by rotating
the bell crank slightly higher in its arc. In effect, installing
longer link arms makes the shock feel stiffer initially without changing how it feels later in the stroke. At the same
time, longer link arms lower the rear of the bike.
( 5) Performance. Before MXA resorted to a longer
link, we were shortening the CRF450’s Showa shock. This
was a drastic solution for a shock that was already 45mm
shorter than the year before. The Pro Circuit link lowered
the rear of the seat, increased compression damping in
the initial part of travel and gave us more tuning possibilities. With the link installed, we slid the forks up 2mm
to keep the same head angle, lightened the high-speed
compression and reset the sag. Overall, every MXA test
rider preferred the 2017 CRF450 with the Pro Circuit link.
WHAT’S THE SQUAWK? No complaints.