Vorsprung have made a name for themselves in the world of mountain bike suspension, offering tuning, servicing and aftermarket parts for forks and rear shocks. In the pursuit of an air spring with "coil-like" sensitivity, Vorsprung have released their all-new Secus air spring for your fork, which they claim actually has a BETTER spring curve than a coil. Read more below...
"Yeah, we know - “coil-like feel” from air springs has been marketed for years now, including by us. And over the years, air springs have mostly gotten closer to that predictable, plush feel coils give. But while the easy adjustability of pressure and end-stroke ramp have always been significant advantages for air springs, even our market-leading Luftkappe and Corset air springs never quite matched the linearity of coil springs for bump compliance, particularly in the early and mid travel. The reason for this is because whenever the initial stroke stiffness was reduced, the ending stroke progression was increased - eventually creating a practical limit on negative chamber size. We looked carefully at the limitations of traditional fork air springs to work out how to overcome those obstacles, and we’re excited about what we were able to achieve.
For the first time, we created an air spring with a truly better spring rate curve than a coil, without it actually being worse in any part of the travel.
Yes, you read that correctly.
Yes, it’s a big claim.
Yes, we can back it up.
It’s called the Secus.
Three Stages of Control
Initial stroke - enlarged negative air spring chamber delivers a soft, supple initial stroke for ultimate small bump compliance
Mid stroke - where traditional air spring rates drop off in the midstroke, our proprietary Midstroke Support Valve technology boosts the midstroke spring rate to maintain linearity, for support, predictability, ride height and compliance
End stroke - enlarged lower leg volume reduces overall progression even at higher pressures and allows for a wider range of end-stroke ramp options to be utilised with standard fork volume spacers.
What’s it all mean? The Secus upgrade attaches to your factory air shaft assembly to deliver 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.
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.
• Distinctly improved small bump compliance, particularly in the early travel (yes, even compared to the Luftkappe)
• 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
• Considerably lighter than coil conversions - adds approximately 130g
• Allows more lower leg bath oil to be used for superior lubrication
• 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
• Costs more money than not having it
• 130g is still more than 0g
• Can be damaged if you have it, can’t be damaged if you don’t
• Still has seal friction like any air spring - since we use the factory moving seals, friction is unchanged
• Bottom out control is not externally adjustable - need to use volume spacers which still entails removing the top cap
**12 Month Crash Replacement Guarantee**
We will replace any damage to your Secus in the event of a crash or accident for the first 12 months of ownership - no questions asked. Just email us a photo of what’s damaged and your proof of purchase and we’ll do the rest.
• Most Fox forks with Float NA2/Evol air springs (except StepCast forks or forks with footbolts recessed in the lowers). 32/34/36 available immediately, 38 and 40 fitments coming soon.
• Most Rockshox Debonair 2019-21 forks or prior year forks updated with 2019-20 Debonair air shafts. Pike, Revelation, Lyrik, Yari available immediately, Boxxer fitments coming soon.
• Not currently recommended for use with 2021 Debonair C1 shafts due to inadequate topout control and incorrect overall length - 2021 forks need to be retrofitted with the Debonair B1 air shaft assemblies from 2019-20.
• For full compatibility information, see our website.
Air or Coil? Secus or Smashpot?
We aren’t purists on the air vs coil debate - we offer the Smashpot coil conversion as well, because while this is flat out the best performing air spring on the market, air springs still have moving seals and the friction and service requirements associated with that. Likewise, coil springs work extremely well and have no friction, but are less adjustable in their spring rate and heavier."