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Find your recommended Ergon saddle.

ST Core Prime Women black

The ergonomic saddle revolution

Cycling has never been so comfortable with the revolutionary ST Core Prime, perfect for demanding touring and e-bike riders. Our unique new formula that alleviates seat pressure, relieves sensitive soft tissue areas and prevents back pain lets you enjoy even the longest tour as if you were floating on clouds.

Price $ 149.95(Without VAT**)
€ 149,95(With VAT**)

Buy online

  • Ergon USA


  • Eliminates numbness
  • 3D-support and freedom of motion
  • Completely new riding experience


Ingenious Working Principle

Floating ergonomic saddle core

When pedaling, your weight is continuously shifted from one sit bone to the other – with the highest stress on the pedal-up side, where your body weight is focused and high pressure occurs. This localized pressure is noticeably reduced by the Ergon Core: Through the suspended Core design and the high-end material properties the bike saddle has the ability to adapt to every pelvic motion when pedaling – enormously enhancing comfort.

Innovative Material – Infinergy®

Cycling as if on clouds

The innovative material Infinergy® by BASF is a new benchmark in suspension and damping in the field of cycling. The elastic seat core supports the pelvic motion when pedaling, absorbs shock and offers relief for your back. When pressure compresses the saddle’s core, consisting of thousands of foam spheres, it will immediately rebound into its original shape – even after a prolonged period of compression. All over the globe leading running shoe manufacturers are also using this E-TPU-foam with great success.

The advantages of the twinshell

Ergon TwinShell vs. Standard Saddle

The revolutionary Ergon TwinShell-Technology raises comfort to a new level. On a typical saddle the shell is directly attached to the rails, carrying the full load of the rider. Therefore it needs to be very stiff and strong. The Ergon ST Core Prime has uses two shells: The lower shell is very stiff and supports all loads while the upper shell supports only the top padding and is intentionally flexible. Between the two shells sits the ergonomic floating core made of Infinergy® – absorbing shocks from beneath, damping vibrations, supporting the pelvic motion when pedaling and noticeably reducing pressure on the sit bones.

The Froböse Formula

Seal of Quality for improving the quality of life

Ergon has developed the ST Core Prime in cooperation with Prof. Dr. Ingo Froböse, a renowned university professor and health expert. His take on the on the ST Core Prime touring saddle is: “By doing elaborate studies and through the scientific cooperation with Ergon, we have created a wonderful product – one that numbness, paraesthesia and health related discomfort don’t stand a chance against.“ The Froböse Formula” is a scientific seal of quality for products in the field of exercise/training, nutrition and recovery and the mark for improving the quality of an active life.

The isolated Damper

Saddle following the pedaling motion

The view from underneath the ST Core Prime clearly shows: The high-performance elastomer isolates both shells completely. This layered construction with its elastic core allows the seat to follow the natural pedaling motion more ergonomically in every direction, efficiently absorbing shocks and vibrations from the terrain.

Orthopädischer Schaum

Komfortabel und robust

The padding of the ST Gel is made of orthopedic comfort foam, which we have designed for fitness bikes, e-bikes and touring bikes. The foam is supportive, soft, but does not collapse. In addition to the foam, specific gel pad inlays offer even more comfort under the sitting area. With this saddle, it is not absolutely necessary to wear cycling shorts. The saddle is covered with robust microfiber to prevent abrasions and maintain the durability of the saddle.

Ergon ST Core Prime-Sattel mit orthopädischem Schaum.


This is how ergon reduces saddle discomfort

When cycling the largest proportion of body weight rests on the relatively small contact area. If this weight is not distributed evenly onto the seat bones, it generates pressure peaks in the highly sensitive perineal and genital area – often leading to discomfort. A sculptured relief channel helps, but is not the only important factor.

For a healthy pressure distribution there needs to be a good balance between sit bone width and upper body tilt. Any ergonomically correct seat should provide adequate surface area while still giving your thighs the space to move freely. Cycling is not a static activity. Uphill the rider intuitively moves forward in order to shift the center of gravity to the front while downhill it’s exactly the opposite.

At Ergon we take all this into consideration when developing a bike saddle. We design specific models for every rider type – for the commuter to the professional athlete. Our saddles come in different widths and have no multi-stepped surfaces, enabling dynamic seating and by their ergonomic shape allow variable riding positions.

Anatomically optimized for men and women

In the saddle contact area men and women are anatomically very different. Any incorrect pressure distribution in this area often leads to feelings of numbness and discomfort when cycling. In scientific tests, through countless prototype saddle designs and in elaborate field tests Ergon has studied – in great depth – the specific needs for both men and women, resulting in two different saddle designs with distinct relief channels, but with one common goal: maximum riding comfort.

Geprüft Rückenfreundlich: Aktion Gesunder Rücken

Rückenschmerzen sind Volkskrankheit Nummer 1. Besonders beim Radfahren wird so der Fahrspaß schnell getrübt. In einem langwierigen Prüfungsverfahren durch ein interdisziplinäres Expertengremium, bestehend aus Medizinern, Orthopäden und Physiotherapeuten, wurde die rückenschonende Wirkung des Core Sattelprinzips nun offiziell bestätigt.

The Right Size

The shape and size of the saddle must match the sit bone width of the rider to maximize comfort and enjoyment.

The pelvic bone has a unique V-shaped and the saddle must offer the sit bones a large contact surface with the ability to meet the demand of different sitting positions. Various saddle widths are offered so that the usable seat surface corresponds to the riders unique sit bone distance.

The more forward and aggressive the rider sits, the further forward the sit bones contact the saddle.

Größen zwischen small / Medium 9-12 cm und Medium / Large 12-16 cm


Play Video

Prof. Dr. Ingo Froböse and Ergon experts explain the ST Core Prime’s joint development and its revolutionary advantages.

Play Video

Field testing in California: Ergon staff members took the ST Core Prime directly to American riders performing spontaneous field testing: See for yourself …

Technical Specifications

ST Core Prime Women
Length: 271 mm Width: 174 mm
Touring, Urban, E-Bike
BASF Infinergy® (E-TPU / Closed Cell Particle Foam)
Nylon Composite
Orthopedic Comfort Foam
women specific
$ 149.95(Without VAT**)
€ 149,95(With VAT**)

**Price can vary by country.


„Ride a bike. If you are alive - you won’t regret it.“

— Mark Twain