Vorsprung Secus Fork Air Spring Upgrade Kit

  • Sale
  • £285

Please contact us before ordering to confirm availability. We are experiencing delays in some variants, with delivery dates subject to change.


10mm shaft clamp required for fitment

For the first time, we created an air spring with a truly better spring rate, everywhere in the travel, than a coil. The Secus upgrade delivers the first and only air spring system to really come indistinguishably close to the linear spring rate of a coil fork for the entire first 2/3rds of its travel, with the advantage of a gentle end stroke progression to prevent bottoming without the “wall of force” harshness that excessively progressive springs create.

Secus Advantages:

  • An enlarged negative air spring chamber delivers a soft, supple initial stroke for ultimate small bump compliance (yes, even compared to the Luftkappe)
  • Proprietary Midstroke Support Valve improves predictability and support beyond the sag point
  • Reduced lower leg pneumatic ramp means better scalability of the air spring, particularly for light riders who previously struggled to use full travel
  • Plush and predictable like a coil, bottomless like an air spring
  • Allows full use of travel in both directions - fully extends to topout without any quibbles (including on Debonair B1 air springs) and fully compresses without excessive ramp
  • Allows more lower leg bath oil to be used for superior lubrication
  • Considerably lighter than coil conversions - adds approximately 130g
  • Simple setup - inflate fork, bounce on it a few times, press MSV charge button, go ride
  • Compatible with OEM volume spacers for end-stroke progression adjustment
  • Compatible with other aftermarket top-cap systems such as DSD Runt and MRP Ramp Control
  • Lower compression ratios mean a more consistent spring rate
  • Transferrable between any Secus-compatible forks with only a footstud to change at most

Three Stages of Control

By independently optimising the beginning, middle and end portions of the stroke, the Secus gives you the linear-to-progressive spring rate that coil springs and traditional air springs alike wish they had. 


Fork Year & Specification Secus Variant
Fox 32 2018+ (unless footnut on spring side is recessed) Fox A1
Fox 34 2018+ (unless footnut on spring side is recessed) Fox A1
Fox 36 2018+  Fox A1
Fox 38 2020+ Fox A2
Fox 40 Available to Order - 2018+ Fox A3
Fox 32 StepCast  Not Compatible
Fox 34 StepCast Not Compatible
Marzocchi Z1 2019+ Fox A1
Rockshox Pike / Revelation 

2019-20 compatible

2014-18 Pike requires 2019-20 (B1/B2) Debonair Airshaft update to be compatible

Note: C1 Debonair update (MY2021) not compatible - use B1/B2 sealhead or air shaft assembly.
Rockshox A2
Rockshox Lyrik / Yari

2019-20 compatible

2016-18 requires 2019-20 (B1/B2) Debonair Airshaft update to be compatible

Note: C1 Debonair update (MY2021) not compatible 
- use B1/B2 sealhead or air shaft assembly.

Rockshox A2

Rockshox Boxxer 2019+ Rockshox A2
Links: WARNING: VORSPRUNG products should be installed and serviced by a trained bicycle service technician, in accordance with both VORSPRUNG and original manufacturers' specifications. If you have any doubt whether or not you can properly service your suspension product, or you have not performed this kind of work before, then please DO NOT attempt it. Improperly serviced products can fail, causing the rider to lose control resulting in SERIOUS INJURY OR DEATH. That's not a joke. Don't mess around with it if you don't know what you're doing, because the best case scenario is usually that you damage something in the process. Do not perform any kind of service on your suspension whilst drunk, high or stupid. We accept no responsibility nor liability for component damage or failure of any description in the case of self-installed units.