Is Specialized working on a new suspension seatpost for road and gravel?
The top bike companies are forever looking at ways to isolate the rider from unforgiving surfaces and there have been countless examples of this in recent decades. In the road world, we often see such new ideas appear at Paris-Roubaix and other cobbled classics, while the surge in gravel riding is fast creating consumer demand for similar comfort and control-based technology, too.
As covered by Matthew Loveridge of BikeRadar, it seems Specialized’s engineers have been busy trying to find a matching seatpost-based partner to the fork steerer-based FutureShock suspension technology found on its Roubaix and Diverge bikes. A published patent application shows a design that employs a flexible or pivoting seatpost that floats within the seat tube and combines it with a small hidden shock dampener.
That patent application
The abstract of the patent application summarises this new design nicely. “An upper portion of the seatpost is movable relative to the frame between a first position and a second position. The damping member couples the seatpost to the frame to dampen movement of the upper portion of the seatpost. The damping member can be positioned at least partially in a toptube of the frame.”
Specialized’s patent application calls for the seatpost to be secured in place at least 30% of the way down the seat tube (and ideally more than 55%), something that provides the design with a long lever to flex or pivot from. Taking things to an extreme, the patent shows the seatpost clamping collar positioned inline with the front derailleur braze-on, producing one incredibly long flexing lever. And the design allows space for that flex by stating that the seat tube must offer at least 25% more front-to-rear width than the dimensions of the seatpost.
Additionally, the patent suggests that the amount of available movement could be adjustable through a series of bushings. “In the event that a rider perceives that the seatpost is flexing too little or too much, the bushing can be replaced with a softer or stiffer bushing to achieve the desired amount of flexing of the seatpost,” reads the patent.
The seatpost would have its natural starting position and then flex in a backward arch under load and impact. The top-tube-based dampener would have a fairly simple task of controlling the back-and-forth movement and could potentially be made impressively small and light. That dampener could be a simple coil spring and elastomer design, but would more likely be a more controlled hydraulic-based unit to match the latest FutureShock 2.0.
Specialized’s existing FutureShock technology provides vertical suspension to the stem and handlebars, effectively isolating the rider from the impacts and significant vibration that the front tyre doesn’t absorb. Similar suspension has long existed in seatpost form, but such designs are inherently flawed as they put saddle height into flux. A number of companies, Specialized included, have previously offered elastomer and/or linkage-based suspension seatposts to overcome these issues, but few have received widespread market acceptance.
Specialized’s concept of letting a flexible seatpost float within the seat tube isn’t a wholly new concept either. The company uses a similar, albeit simpler strategy on its existing Roubaix endurance road bike, while both the new Canyon Aeroad and Giant TCX Advanced work on a similar concept, too. Then there’s Trek’s IsoSpeed design that decouples the seatpost from the top tube, allowing it to effectively pivot in place and act as a leaf spring.
However, Specialized’s concept has the potential to offer vastly more seated comfort without risk of introducing a wallowing or motion-sickness-inducing feeling to the bike. What it won’t do, however, is offer any benefit to rear-wheel traction, and for that it’s applications outside of road and gravel bikes are likely quite limited.
Will we see this on the next generation of Roubaix endurance road and Diverge gravel bikes? Your guess is as good as mine. The concept looks promising and would indeed make sense as a match to the FutureShock concept. Given it’s been almost three years since Specialized put the patent application in, the design is quite possibly ready for prime time.