— Single-seat Polaris gets Shock Therapy —

Polaris is enjoying great success with the RZR RS1 single-seat UTV, with Ronnie Anderson winning the first and last two WORCS Pro 1000 UTV rounds. The RS1 has proven itself a great duner and rock crawler as well, with the view out of the cockpit and short wheelbase allowing for precise placement and handling. We were stoked with the ride of the HCR Racing RZR RS1 (UTV Action, September 2018) at Moab’s legendary rock formations, as the stock Walker Evans Racing shocks worked very well with the HCR long-travel suspension kit.

The Polaris RZR RS1 has proven itself a very capable duner, rock crawler and short-course racer, with unequaled visibility from the cabin and turbo-grade components. Shock Therapy makes it even better with shock valving and spring kits, torsion bars and travel limiters.

Then we drove an RS1 at Camp RZR that blew our minds. Shock Therapy has done a lot of testing and development work with the RZR RS1 and had the Shock Therapy RS1 build on hand at Glamis Sand Dunes. The ride was simply amazing.


First, Shock Therapy does its magic to the Walker Evans needle shocks; Shock Therapy’s Stage 1 Ride Improvement System (RIS) involves extensive modifications to the pistons, shock shafts and compression adjusters to get more oil flow throughout. The goal is to eliminate the harsh ride over dune and desert chop while increasing the bump stage to fight bottoming on G-outs. The more progressive valving eliminates the need to close off the compression adjusters to fight bottoming, so the overall ride is plusher in small chop and big dunes. The cost is $649.95.

Shock Therapy’s front-travel limiter kits have top and bottom mounts that raise the price a bit over rear limiter kits, and the Gold ST sticker on the shock reservoir means ST has worked its magic with the shock pistons, shafts and compression-adjuster assemblies.

Stage 2 adds Shock Therapy’s Dual-Rate Spring (DRS) kit to the shock work. The Shock Therapy RS1 kit includes eight proprietary springs and four silent cross-overs to deliver true dual-rate spring performance with adjustable cross-overs. This smooths out the initial reaction to chop even more, and stiffer main springs improve bottoming resistance at the other end of the stroke. The RS1 DRS kit is $899.40, bringing the four-shock total to $1,449.35.

With no engine or exhaust mods, the ST RS1 wheelies and upgraded torsion bars improve tracking considerably. Front 30-inch Tributes by Sand Tires Unlimited were cut for improved forward bite when they were actually touching the ground.

With the Shock Therapy RS1 ride floating over everything, it’s time to hook up the handling even more. Shock Therapy has developed new front ($200) and rear ($550) torsion bars that put the RS1’s handling on rails. Shock Therapy is impressed with the stoutness of the RS1’s front torsion-bar links, but Shock Therapy’s front links are billet aluminum and adjustable. They also have an hourglass shape machined into them to clear the large front axles at full compression. At the other end, there is full extension when jumping in the dunes. Shock Therapy has developed its RS1 adjustable front limit-strap kit ($299.95) to keep the front end from clunking, as the WER shocks don’t reach their top-out stops. Rear limit strap kits are $249.95. This is especially annoying with aftermarket tires and wheels. Speaking of which, the ST RS1 was fitted with 31-inch Tribute front paddles cut directionally for better forward bite and rear Blackbirds on DWT sand-car aluminum rims that are thicker and stronger than UTV wheels.

Shock Therapy is impressed with the RZR RS1, as it has the same rack-and-pinion steering, front diff and axles as the RZR  XP Turbo. Shock Therapy is also developing a billet-aluminum steering rack for the RS1.

See the red O-ring on the bottom of the ST Silent cross-over? It eliminates any clicking sound when the spring collar bottoms on the ring. Spring rates and shock valving make the initial travel much plusher and resist bottoming without any spikes.


Shock Therapy did an amazing job on the ST RS1; it does anything you want in the dunes. It’s great in G-outs and transitions, and it turns like it can read your mind. With the Tribute and Blackbird paddle tires, it wheelies in dunes like an XP Turbo. In fact, the Shock Therapy RS1 is better than the RZR XP Turbo in sand whoops. The stock Turbo kicks and bucks on Sand Highway, despite a longer 90-inch wheelbase. The Shock Therapy RS1 is rock solid and super stable on Sand Highway, as it wheelies into each whoop face like a dirt bike and stays ruler-straight. Even chopping the throttle doesn’t adversely affect the ride. It’s phenomenal!

The shock work, torsion bars with front links, and limit-strap kit will cost you a tad under $2,900. Add that to the RS1’s $14,299 MSRP, and you get a dune rocket for less than $17,200!

SR-30 Blackbird rear paddles ride on DWT aluminum dune rims, and the setup is slightly lighter than the stock 29-inch Bighorns on Polaris aluminum wheels for better traction, flotation and acceleration in dune sand.


Shock Therapy

23011 North 16th Lane

Phoenix, AZ 85027

(623) 217-4959

[email protected]



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