Ergon ST Core is like running shoes for your butt

New Twin Shell design borrows technology from footwear

Bike saddles as a whole seem a bit backwards when it comes to their design. The lightly padded seats are more comfortable than the thick squishy ones, and riders choose to sit for hours on monstrosities with two noses and holes drilled through the middle that are more akin to medieval torture devices than seating arrangements.


German brand Ergon has come up with an innovative design that doesn’t involve any radical shapes, holes or technologies, instead, it’s looked to running shoes for a comfort solution.

The brand’s new Twin Shell design sees two independent shells held in a floating arrangement by a high-performance elastomer damper made of Infinergy. Also used by Adidas in its Boost shoes, Infinergy is an expanded thermoplastic polyurethane (E-TPU) developed by plastics company BASF.

The lower, supporting shell performs a load-bearing function while the upper, flexible seat shell supports the padding. Essentially, this allows for thin padding on the top and good support of the sits bones, while the lower section offers some dampening.

Sandwich design

By having two separate shells (a “carrier shell” and a “seat shell”) the seat shell to actually float seperate to the saddle rail attachments

Franc Arnold, Ergon founder, said: “The idea of a design principle using TwinShell technology and an ergonomic core has been around for a while, but we were never able to find a suitable material on the market to implement this project.”

“German Innovation is not just a slogan for us, Ergon has a strong German R&D network, with specialists in different areas. BASF German head office is our partner for material science.” Arnold continued. “Our revolutionary Core TwinShell concept could be perfectly realized with the latest INFINERGY TPU technology from BASF, which is already successfully used in the running shoe industry. The ergonomic Core sandwich layer is exclusively produced for us in Germany.”

Ergon says this new design not only increases comfort but allows for a new form of pedalling ergonomics. With the two independent shells and the squishy material sandwiched in the middle, it says the saddle follows natural pedalling movements in every direction.

According to BASF, Infinergy is a highly elastic material and will spring back to its original shape under continuous load and after repeated impact.

Ergon has confirmed the ST Core is targeted at the fitness, commuter, ebike crowd, but depending on how well the technology works seems like a great idea for road and gravel applications.

The saddle is set to be available in February 2018 in two men’s sizes and two women’s sizes and will cost €149.94.


Ergon will be showing the saddle at Eurobike.