Air, Coil, or Both? New PUSH ACS-3 Coil Spring Fork Conversion Kit

Suspension wizards PUSH Industries have been eking the most out of mountain bike forks and shocks since 2003. In 2016, PUSH ventured into making their own suspension components with the wild ELEVENSIX coil shock. Based on the success of the ELEVENSIX, PUSH has developed the ACS-3, a drop-in coil spring conversion kit for Fox 36 and RockShox Pike forks.

The popularity of the Elevensix rear shock lit a fire under us to offer that same level of performance to the front end of our customers’ bikes. The ACS-3 takes two already noteworthy products, and then adds yet another level of performance. It makes the awesome awesomer.
-Darren Murphy, PUSH Founder

Why a Coil?

It’s hard to beat the suppleness of a quality coil shock or fork. They provide ground-hugging traction and react seamlessly to the terrain. Of course the downside is that a metal coil spring is heavier than air, and its linear nature means no ramp up at the end of the stroke like you get with an air spring. An air spring is certainly lighter and faster to tune, but the high pressures also create stiction in the seals which makes the suspension slower to react.

PUSH’s ACS-3 kit effectively combines the two — coil and air — into one unit. The coil provides supple, linear suspension off the top and through the mid stroke, while the pneumatic bump stop will ramp up the spring rate to prevent bottom out at full travel. PUSH offers seven different spring rates for the coils and the bump stop can be tuned between 5 and 50 PSI. This allows riders to fine tune their fork for their weight, riding style, and terrain.

The kits retail for $389 and additional springs run $80 apiece. PUSH has kits for 2015-2017, 160mm travel, Fox 36 forks available now, with additional Fox kits arriving in a couple weeks. RockShox kits will follow soon after.


Dropping in the ACS-3 looks to be a straightforward procedure, assuming you’ve worked on a fork before. When installing the kit, PUSH recommends doing a lower leg service simultaneously since you’ll already have your fork apart. PUSH has a new Lower Leg Service Kit that will allow you to do just that. The $105 kit includes seals, a seal press, foam rings, oil, and grease. There’s enough oil and grease for five services, and additional seal kits are $36 each. PUSH claims their seals double the service intervals over their stock counterparts, so it sounds like a good value for the home mechanic.

Check out the video below for the complete installation procedure with PUSH founder, Darren Murphy.

ACS_Instal_How_to_video from PUSH Industries on Vimeo.

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