Yamaha stunned the world with its puresport YXZ1000R, and we are mightily impressed with its performance in the dunes and early results in short-course racing with minimal modifications. Its suspension is set up for hard-core dune and race enthusiasts, and we never came close to bottoming its Fox 2.5 Podium RC2 shocks with the rear Bottom-Out Cup (BOC) technology at the Imperial Sand Dunes or the Arizona desert. Yamaha worked with Fox Racing to develop the exclusive shocks with oversized DualSpeed Compression (DSC) assemblies in the piggyback reservoirs, and high- and lowspeed compression knobs have four turns of adjustment. Stock settings are 1.5 turns out on the LSC at both ends, and 2.0 turns out on the front HSC and 1.5 turns out on the rear HSC. Backing off completely to four turns out won’t soften up the ride enough for nonaggressive drivers, and there’s a 400-pound pop-off spring in the DSC assembly and valving that won’t flow enough fluid to soften the ride for desert chop.
FLOWING FOR A PLUSHER RIDE
Shock Therapy has machined new DSC components to allow for larger valve stacks and greater flow through the DSC, eliminating the over-damping for not-so-aggressive drivers and smoothing out the ride in desert crossgrain terrain. ST is also developing a much stiffer front torsion bar to prevent diving and body roll with the softer compression damping, dubbed Shock Therapy’s Ride Improvement System (RIS). For the RZR XP Turbo and Fox Edition, the RIS is only $749.95, and the RIS for the Yamaha will be the same.
ST is also developing Level 2 spring kits that add dual-rate springs with cross-over collars to the OEM rear spring, and it goes for $399.95. Level 3 isn’t possible with the YXZ1000R, as the front springs don’t leave room for dual-rates. Level 4 DRS (dual-rate spring) replaces all OEM springs with eight ST custom springs and silent cross-over collars for $1,049.95. Mated with the RIS valving for the YXZ1000R, the spring kits make the Yamaha ride like a magic carpet over the most hideous desert chop.
TORSION BAR HANDLING UPGRADES
Shock Therapy also upgrades the suspension by massaging the rates on torsion bars. On the RZR XP 1000 and XP Turbo, ST doubles the rate on its rear torsion bar and has developed a highly tunable front torsion bar. For the Yamaha, ST increases the rate on the front torsion bar is 3/4-inch in diameter and has four link holes for adjustability. Between the torsion bars, RIS valving and DRS, ST makes the YXZ1000R float over obstacles and impacts like a hovercraft, yet be completely hooked up to the trail for steering input, braking and acceleration. It’s a total transformation that even leadfoot hammerheads will appreciate.
Also, Shock Therapy is a dealer and tuner for Walker Evans Racing, which already has Velocity Series 2.5 shocks for the Yamaha YXZ, and for King Racing. They’ll be developing valving and spring rates for both brands to upgrade the YXZ1000R even more, but we’re going for the most economical Rx at this time and will be adding long travel with HCR/King Racing next month.
Shock Therapy Suspension Tuning, LLC P.O. Box 116 Wittman, AZ 85361