SPECIAL NOTE: Installing the ACS3 Coil Conversion kit will VOID the 2-year Rock Shox warranty. The kit does not pose any structural/safety threat to the fork, but since it is not built by Rock Shox, the warranty will be voided on your fork. It is also not recommended to switch back to the stock air assembly after converting your fork to the ACS3 Coil.
The folks at Push have upped the ante yet again. Ever since the release of the ElevenSix rear shock, we've been longing for a fork that can match the performance. While not quite as exciting as an Push fork built from the ground-up, what we have here is about as close as you can get for the time being. The Advanced Coil System (ACS) drops right into your fork, converting it to a coil system. It's not just any coil system though - this is done in true Push fashion, fully manufactured to perfection in-house at their Colorado facility.
Over the years, we've seen manufacturers largely switch to air sprung forks, in an effort to keep the fork as light as possible. No matter how you shake it though, it is incredibly difficult to match the small bump sensitivity that a coil spring provides. Companies like Fox and Rock Shox have dumped countless hours into developing highly advanced air spring systems in their forks. And while the folks at Push acknowledge that these air spring systems have gotten very good, it's still not as good as coil, and that their ACS3 coil damper provides a noticeable gain in small bump sensitivity. Push uses a super high quality high tensile CrV-SI spring wire, which they claim provides the best possible initial bump sensitivity, as well as predictable control throughout the entire stroke.
The ACS3 also features a pneumatic bump stop, adjustable between 5 - 50 psi. This effectively acts like bottom out spacers in an air fork, adjusting the amount of ramp-up, or bottom out resistance. Simply use a standard shock pump to set your bump stop pressure from the top cap of the system. This air cap is not to be confused with the air cap you're used to on your air sprung fork. The ACS3 is available for rider weights 125 - 230 lbs, in 15 lb increments. Inside each of these increments are varying weights of coil springs, which will be required to make the fork feel right for you. Springs are available separately, should you need to change at any point down the road.
All in all, the ACS3 will add on between 210 - 285 grams to your Rock Shox Lyrik, depending on the spring rate selected. We feel that's a fairly minimal weight penalty, considering most coil forks in the past were at least 450 grams heavier than the the air-sprung versions.
This ACS3 kit can be used with 2016 - 2018 Rock Shox Lyrik/Yari, RC and RCT3 forks, both 27.5" and 29". Please note, the required spring rate will vary depending on your weight, as well as the current travel of your fork. You can view the Spring Rate Chart by clicking the link above.