S311 is a bicycle seatpost with an integrated rear-light (with 5 LEDs). There are 3 types of S311: S311, S311E, S311D. The power source of S311 is an integrated rechargeable battery, the battery can be charged via a micro-USB port. S311E is connected to an external power source via a connection cable, for example to the battery of an e-bike. S311D is powered by a dynamo hub.

Seatpost test standard ISO 4210 mountain or ISO City
LED-unit There are 2 modes to choose from:
– 5 LED mode (all 5 LEDs light up)
– 3 LED mode / energy saving mode (only the top 3 LEDs light up)
Function The second top LED functions as a button and is used to operate the real light.
Light modes:
Off → 5 LEDs → 3 LEDs → Long press to witch off
Power source Lithium polymer battery 3.7V, 800mAh
type: 801473, with integrated overcharge protection
Light duration
(fully charged battery)
5 LED: 10 hours
3 LED: 15 hours
Charging Micro-USB 2.0 port integrated in the seat rail clamp with a transparent silicone cover for splash-water protection.
Charging voltage: 5 V
Charging current: 0.5 A – 2.0 A
Charging time 2.5 hours
Charge state Indicated by a blue LED integrated into the micro-USB port.
As soon as this LED lights up, the battery still has enough capacity to power the LEDs for 1 more hour in accordance with the regulation.
The micro-USB port is covered with a transparent silicone cap so that the blue LED is visible.
Package contents Rear light seatpost, USB charge cable (200cm)
Approval code K1595


Seatpost test standard

ISO 4210 mountain or ISO City


Lights up when AC power is supplied

Power source

Dynamo AC

Power consumption


Nominal voltage

AC 6V (3W)

Package Contents

Rear light Seapost, extension cable (200mm)

Seatpost test standard EN 15194 or ISO 4210 mountain

The Rear light is operated by the light switch of the e-bike system.

The Rear light does not have modes.

Power source On-board battery of the e-bike. The Seatpost can be operated with on-board voltages (direct current – DC) from 6 V to a maximum of 12V. The electrical connection is made with different cables and connectors in compliance with the relevant regulations.
Power consumption 0.3W
Nominal voltage DC 6V (6 V – 12V)
Package Contents Rear light seatpost

Special seatpost design of S311

Patented seatpost with an integrated seat rail clamp. The seatpost tube features 5 holes in which the LEDs are enclosed.

S311’s USB 2.0 charging port is in the lower section of the seat rail clamp. The port is accessible from the outside and can be closed using a transparent silicone cover.

S311E or S311D’s cable with a connector extends out of the lower end of the seatpost tube for connection to the electrical system of the e-bike or the bicycle dynamo.


Diameter (see drawing)  25.4㎜ / 27.2㎜ / 30.9㎜ / 31.6㎜
Widths (see drawing)  350㎜ / 400㎜ (D30.9mm / D31.6mm)
Color and surface finish  polished Silver / anodized Black.
Material  Aluminum 6061 T6

LED unit
5 LEDs with integrated electrical light control and battery management system. The two upper LEDs are protruding, also ensuring the lateral emission of light. The lower 3 LEDs are sunk into the seat post tube. The LEDs, circuit board and battery are enclosed in a plastic housing and are thus protected. (dust and splash proof in accordance with IPX5).

Operating temperature Min.: -15°C, Max.: 45°C
Optimum storage temperature: 20-25° C
Compliant with standard or directive RoHS, UN3481, StVZO §22a TA 14b (Bicycle rear light), IPX5



Angle limits (frame seat tube) according to the StVZO

Min: 70.0°
Max: 76.0°