MXA TEAM TESTED: MX-TECH KTM 350SXF FORK/SHOCK MODS


WHAT IS IT?
MX-Tech is one of a handful of suspension companies that specialized in fixing WP components.

WHAT’S IT COST? $250 (fork revalve); $250 (fork Huck valve); $50 (fork sub-valve); $109 (fork springs); $250 (shock revalve); $109 (shock spring); $200 (shock Head Check system).

CONTACT? www.mx-tech.com or (877) 850-5114.

WHAT STANDS OUT?
Here’s a list of things that stand out with MX-Tech’s KTM 350SXF setup.

(1) Huck valve. MX-Tech’s Jeremy Wilkey doesn’t just change shims on a WP fork; he reinvents the fork altogether. Apart from the normal valving, springs and oil height changes, MX-Tech adds its Huck valve. The Huck valve replaces the stock cone-shaped bottoming device that depends on the hydraulic lock to work. The Huck valve uses a shim stack to ensure that the forks get all of their travel without harsh bottoming. The shim stack makes the bottoming system speed sensitive instead of position sensitive.

(2) Fork revalve. The stock KTM forks have light damping through the mid-stroke, which means that they depend on heavier damping at the extremes of travel. MX-Tech stiffens up the mid-speed valving while lightening up the base valve damping. The result is a more progressive flow?especially when mated to the buttery-smooth Huck valve bottoming control device. To help the compression clicker, MX-Tech incorporates a sub-valve that prevents free bleed as the clicker is turned out. This sub-valve widens the clicker’s sweet spot, making the difference between clicks noticeable.

(3) Fork springs.
It’s no secret that KTM spec’ed the wrong springs for the 2011 KTM 350SXF . They are too soft for a bike of this size and power. Instead of 250SXF spring rates, the heavier 350SXF needs 450SXF springs. MX-Tech recommends 0.50 kg/mm springs in place of the stock 0.46s.

(4) Shock.
The two biggest complaints with the 2011 KTM 350SXF shock are that the spring rate is too light and that even with a stiffer spring, the rear end drops under acceleration. MX-Tech attacks these issues with a 5.7 spring, instead of the stock 5.4, more low-speed compression damping and slightly less high-speed damping. Happily, the 2012 KTM 350SXF comes with the 5.7 spring stock.

(5) Head Check. The Head Check is a unique compression damping check valve (combined with a shim stack). It allows the KTM to have enough low-speed compression to hold the bike high in its stroke, but still be fluid enough to absorb any spike (as measured by a rapid increase in shaft speed). The spike opens up the Head Check valve to relieve pressure. This valve looks like it was made by a Swiss watchmaker.

(6) Performance. MXA has issues with the stock fork’s minimal midstroke valving, the shock’s tendency to suck down under acceleration and KTM’s poorly selected spring rates. MX-Tech addresses every one of these issues. MX-Tech’s valving choices work like magic in conjunction with the stiffer springs. MX-Tech has been the leader in KTM suspension mods, and it shows in the fluidity of their work.

WHAT’S THE SQUAWK? The price is high for the full setup, but just the springs and MX-Tech revalve will make a big difference.

This is the suspension that WP wishes it had built for the 350SXF.

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