Installation

Thank you for purchasing a Ratio Components Flux air spring cap! This product is designed to improve mid stroke compliance and allow for increased travel usage on model year 2020+ RockShox ZEB and model year 2024+ RockShox BoXXer suspension forks with 38mm stanchions.

To install your new air spring cap please carefully follow the instructions below. If you are unsure about how to carry out any of the procedures below, bring your bike to a professional bike shop and have them cary out the installation of your Ratio Components air spring cap.

*The following procedures involve pressurized devices and thus, certified safety glasses should be worn (ANSI Z87.1 / EN166EU)

You will need the following items, which are shown above:

  • High pressure shock pump
  • Torque wrench
  • 32mm socket cap
  • Cassette removal tool, or cassette removal socket cap
  • Small Allen key for depressing a standard Schrader valve core
  • Grease
  • Shop towel or rag

Step One 

  • Unscrew the valve cap from your stock RockShox ZEB (shown) or BoXXER air spring cap.

Step Two - SAFETY WARNING -  IMPORTANT!

  • Release ALL the air from the stock air spring assembly…
  • To do so, use a small Allen key to depress the Schrader valve, or preferably connect your shock pump and press the shock pump’s bleed valve to slowly drain all air until the shock pump reads zero PSI.
  • Warning - failure to release all of the air pressure before disassembly can result in serious injury!

Step Three

  • If you are riding a BoXXer you will need to loosen the 4mm Allen screw on the air spring side of you upper crown before proceeding.
  • Using a cassette tool, loosen the stock air spring cap assembly until it can be removed by hand.

Step Four

  • Remove the stock air spring cap assembly. Take care not to allow any debris or other items to fall into the fork’s stanchion while it is exposed.

 Step Five

  • IMPORTANT - Apply a layer of grease 360 degrees around the o-ring of your Ratio Components air spring cap. Failure to do so can result in a damaged o-ring that does not seal properly, and thus a potential injury.

Step Six

  • Hand thread the Ratio Components air spring cap into your fork for the first few turns until hand tightening is no longer possible..

 Step Seven

  • Make sure that the valve of the Ratio Components air spring cap cap is removed before the next step. This will ensure sufficient contact with the socket wrench...
  • Using a torque wrench and a 32mm socket, set the torque to 28nm and carefully tighten the Ratio Components air spring cap to 28nm.

 Step Eight

  • Check to ensure that the Ratio Components air spring cap assembly does not come into contact with your mountain bike’s down tube by turning the handlebars. Our product was carefully designed so that its taper matches the angle of most mountain bike down tubes, thus providing optimal clearance. With that in mind, we cannot test fitment on every single mountain bike on the market. We recommend a minimum of 2-3 mm of clearance. Should your Ratio Components air spring cap not safely clear your frame we will send you a shipping label to return your product for a refund.
  • IMPORTANT! If you are installing a Ratio Components air spring cap on a dual crown MY24+ RockShox BoXXer, you will not need to be concerned with down tube clearance. However, it is extremely important to verify that your handlebar has 2-3mm of clearance and does not contact the Ratio Components air spring cap!
  • If you are riding a BoXXer you will now need to re-torque the 4mm Allen screw on the air spring side of the upper crown back down to 10nm. 

Step Nine

  • Re-inflate your RockShox ZEB or BoXXer. We suggest starting with approximately 3-5 PSI more air pressure for ZEB and 5-10 PSI more for BoXXer as compared to the factory recommended starting point and/or your preferred pressure with a stock air spring cap and zero volume reducers.

Thank you!