ISTOS E-Dropper Post

ArtNo. 26AC000000001

€259,00

This electronically controlled seatpost offers 75 or 125 mm of travel and is seamlessly integrated into the HEPHA system. It requires neither its own battery nor an additional lever and can be operated quickly and ergonomically via the handlebar remote control.

Choose from the following travel

75 mm 125 mm

Product variants

View details

Easy to get on and off. Comfortable & safe.

The ISTOS E-Dropper replaces conventional mechanical cable solutions with electronic control. With an adjustment range of 75 or 125 mm, you can quickly and precisely adjust your saddle height to the terrain and riding situation – giving you more freedom of movement on descents and making it easier to get on and off your bike in the city. As the dropper seat post is fully integrated into the HEPHA system, it requires no separate battery or additional controls on the handlebars. It is operated via the existing remote control, keeping your cockpit clear and tidy. The release dynamics can be individually adjusted so that the speed at which the seat post extends or lowers matches your personal riding style. For the rider, this means clean integration, easy handling and maximum freedom of movement – without any additional components.

The ISTOS E-Dropper Post can be retrofitted to all HEPHA e-bikes from model year 2026 onwards, as the cables are already neatly pre-installed in the frame ex works. For bikes with P101C motor the app update for adjusting the activation speed will be available from Q2/2026.

Electronically controlled
Seamlessly integrated into the HEPHA system
No additional battery/lever required
Slow and fast activation speed
Easy to retrofit: Plug-and-play

Easy to hop on, safe to ride.

One click and the saddle is at the right height. Magic? Technology.

Highlights

Standing safely at the traffic light

A dropper seatpost makes getting on and off the bike much easier. A lowered saddle is especially helpful when stopping at a traffic light or making a sudden stop, as it allows you to stand securely with both feet on the ground.

Adjust the saddle height while riding

Sitting in exactly the same position on your bike for long periods of time can lead to problems. Thanks to its stepless adjustment, the E-Dropper lets you adjust your seating position in small steps. This helps prevent seating issues and back pain – especially on long rides.

Fast and smooth handling

The E-Dropper seatpost is controlled via the existing remote, keeping your cockpit clean and uncluttered. Thanks to the electronic control system, the seatpost lowers quickly, reliably and with minimal effort.

Easy to retrofit: Plug & Play

Since the E-Dropper seatpost is fully integrated into the HEPHA system, it requires neither a separate battery nor an additional controller. It can be easily retrofitted to all 2026 HEPHA e-bikes, as the cable is already pre-installed in the frame ex works.

Slow & fast activation speed

The release dynamics can be individually adjusted via the HEPHA app (available for P101 motors from Q 2/26). This way, you can be sure that the speed at which the seat post extends or lowers matches your personal riding style.

Specification

Diameter

31.8mm

Weight

500 g (75 mm) / 585 g (125 mm)

Max. rider weight

120 kg

Min. insertion depth

150 mm

IP rating

IP65

Application category

Category 4

FAQ

Can I retrofit a dropper seat post?

Yes, basically all dropper seat posts can be retrofitted. However, with mechanical dropper posts, a cable must first be routed through the frame to activate the mechanism, which is a very labor-intensive process. Be sure to contact a HEPHA dealer for this.
Alternatively, we offer the ISTOS E-Dropper Post. It is electronically activated and is directly integrated into the HEPHA drive system. Installation is particularly easy, as the cable is already pre-routed on all 2026 models: just plug it in, activate it, and you’re good to go.

What is the difference between the two E-Dropper models (75 mm vs. 125 mm)?

The main difference lies in the travel, i.e., the saddle’s drop distance. The longer travel provides more legroom on descents and even greater comfort when mounting and dismounting. Which length fits your bike depends entirely on your frame and seat height. Riders with limited saddle extension will likely need to opt for the shorter version. If in doubt, contact a HEPHA dealer.

Is a dropper seatpost only suitable for mountain bikes?

No, trekking and city cyclists also benefit from a lowered saddle. A dropper seatpost not only makes getting on and off the bike easier, but also makes short stops safer, as you can stand firmly on the ground with both feet.

What seat tube diameters is the ISTOS E-Dropper compatible with?

The E-Dropper has a diameter of 31.8 mm and therefore fits all HEPHA e-bikes.

How is the ISTOS E-Dropper Post controlled - do I need an additional lever on the handlebars?

No. The electronically controlled seatpost is directly integrated into the HEPHA system and requires neither its own battery nor an additional lever. It can be conveniently operated using the system remote control.

What does minimum insertion depth mean?

The minimum insertion depth indicates the minimum distance the seatpost must be inserted into the frame’s seat tube. The E-Dropper has a marking line (“Min. Insert”) for this purpose. This line must no longer be visible when the seatpost is inserted into the frame.

ISTOS E-Dropper Post – Download User Manual

Important: The installation instructions apply only to MY26 models. On older models (MY24/25), the e-dropper may already be factory-installed; in this case, the user manual is provided solely for reference regarding specifications and configuration.

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