MXA TEAM TESTED: MX1 SUSPENSION HYBRID WP FORK KIT

WHAT IS IT? The MX1 Hybrid AER fork kit works on the WP XACT air forks spec’ed on KTM, Husqvarna and GasGas off-road bikes. It addresses the pluses and minuses of air forks by keeping what’s good while adding just a touch of coil-spring tech to the equation.

WHAT’S IT COST? $925.00 (2021–2023 models), $1025 (2017–2020 models). Only the right fork leg needs to be modified.

CONTACT? www.mx1suspension.com or www.dicksracing.com or (916) 705-3193.

WHAT STANDS OUT? Here’s a list of things that stand out with MX1 Suspension’s Hybrid AER fork kit.

(1) Workload. Dick Wilk’s MX1 Hybrid AER fork kit eliminates air pressure’s chronic stiction and ramp-up issues by allowing the fork pressure to be reduced to 65 psi instead of the 154 psi that WP recommends. How can that small amount of air pressure work over big jumps and harsh bumps? It can’t, which is where the magic of Dick Wilk’s combination comes in. The MX1 Hybrid system gets away with such low air pressure in the left leg because Dick combines it with all-new damping and a 5.0 N/mm coil spring in the right leg. 

The coil spring does the majority of the work when the forks move initially, while the 50 to 65 psi of air pressure ramps up as it is compressed. In essence, the two fork legs handle different parts of the workload; the coil spring handles small-to-medium hits, and the air spring handles medium-to-large hits. 

(2) Weight. The right leg of the WP XACT air forks has always had a cartridge rod, fork oil and the necessary shim stack, so the only thing that MX1 Suspension adds to that leg, apart from MX1’s proprietary valving system, is a 5.0 N/mm coil spring. The typical coil-spring fork has cartridge rods, fork oil, shim stacks and coil springs in both legs. That means that compared to a coil-spring fork, the stock WP XACT air fork is over 3 pounds lighter, while the MX1 Hybrid fork is 1.5 pounds lighter.

(3) Performance. MXA had MX1 Suspension build us a right Hybrid fork leg to Husqvarna specs, which means 10mm shorter. We asked for Vet valving. Because the 5.0 N/mm coil spring handles all the initial fork control, the low air pressure doesn’t interfere with the fork feeling like a coil-spring fork. Then, as the front wheel moves upward in its stroke, the air pressure inside the WP leg doubles every time the available air volume decreases by 50 percent. 

(4) MX1 Hybrid forks. We started testing the MX1 Hybrid forks at 50 psi and 10 clicks out on compression. This was a good setting for lightweight riders, but we upped it to 55 psi, 60 psi and 65 psi for faster and heavier riders. Eventually, we focused on selecting air pressure based on keeping the fork from dropping into its stroke. We added two clicks to the compression damping when needed.

Tuning potential comes from four sources: (1) Air pressure in the left leg. (2) The coil spring rate in the right leg. (3) Compression damping via a sideways clicker on the right fork cap. (4) The chosen shim stack and valving.

WHAT’S THE SQUAWK? We don’t have any complaints.

MXA RATING: Test riders loved the adjustable feel of the MX1 Hybrid fork. It uses the best attributes of coil spring and air forks. The MXA hybrid fork kit saves weight over a traditional coil-spring fork, cuts shipping costs, and is less expensive because only one fork leg is modified.