Fox Shock Compatibility

With the current popularity of “strut mount” or “yoke-equipped” bicycle frame designs, Fox would like to highlight important considerations when considering and/or using a coil shock in this application.

First, here are four current examples of what some “strut-mount/yoke-equipped” frame suspension designs look like.

Here are some examples of “strut mount / yoke-equipped” mtb and e-mtb brands that are available in the market.

  • Atala, Canyon, Commencal, Esker, Ibis, Lapierre, Marin, Pivot, Polygon, Propain, Specialized, Yeti

A strut-mount suspension design puts additional structural loads into the shock. The design of air shocks provides greater structural support to better handle the increased loads that one encounters with a strut-mount design than a coil shock can typically provide.

Because of this, Fox has restrictions regarding shock sizing and the strut length.

  • Please check the OEM bike owner’s manual for confirmation of coil shock compatibility.
    • Many OEM models do not allow the use of coil shocks on their strut mount/yoke-equipped models
    • Many OEM models are optimized for an air shock application only
  • Never exceed the shock stroke and strut length combinations as listed below
    • WARNING: Failure to do so will void your Fox warranty
  • NOTE: The “shock stroke” is the amount of travel provided by the shock. Please reference the Fox 4-digit-code to get shock travel specification and/or reference your OEM bicycle website for your specific application
  • NOTE: The “strut length” is the distance between the axis of the pivot and the axis of the shock mount
  • Only metric-sized (mm) shocks can be installed.
  • No imperial-sized (in) shocks meet installation requirements
  • Confirm shock travel and stroke length for the requested model. Never deviate from the original “eye-to-eye length”
  • Confirm you have selected the correct spring weight (requires the use of a spring calculator)
  • NOTE: If in-between spring rates, always select the higher spring rate

Often a strut-mount suspension design tends to provide a “more linear/less progressive” spring curve. Thus when the bike model is equipped with an air shock, the air shock provides added progression as the bike goes through its travel (resisting bottom-our forces).

  • However, if updated with an aftermarket coil shock, there is no natural “ramp-up” of the air spring, so the coil shock tends to quickly go through its complete travel range and can easily bottom-out.
  • If you are looking to upgrade your current shock, there are two options
  • The DPX2 shock has new updates that raise its trail performance higher for MY2021. It offers improved small bump sensitivity, increased oil flow, very lightweight design, and natural progression at the end of the shock stroke
  • The new MY 2021 FLOAT X2 shock is truly an advancement from the previous FLOAT X2 model as well as “blurring” the lines when compared to a coil shock. It’s sensitivity to small bumps and initial stroke feel mimic what a coil shock offers, it allows for small changes in air pressure to set accurate sag per your bike model and liking, provides substantial weight savings, offers progression at the end of the stroke, and perfectly matches every suspension design.

We hope this communication has provided you a better understanding of strut mount/yoke-equipped bicycle designs and coil shock applications.

If you have any immediate questions, please get in touch.