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27.5" Electric Mountain Bike - Blue


This electric mountain bike has been designed and developed by us to best suit mountain bike rides on hilly and rolling terrain.

This electric bike has been designed to enjoy (or relive) your very first biking thrills. The smart electric assistance, driven by a cadence sensor and a control screen, helps you find your pace.

Color: Faded denim
Size: size guide


Product benefits



Overcome your first slopes with the motor's torque of 42Nm at 250 W.



Ride an average of 2 hrs 15 min at a sporty pace thanks to the 380Wh battery.

Smooth pedalling

Smooth pedalling

Enjoy/relive your first MTB rides: smart help with cadence sensor

Cycling comfort

Cycling comfort

Enjoy touring: raised position, 100mm suspension, Ergofit hammock saddle

Directional control

Directional control

Control your trajectory: all-terrain tyres, wide handlebar.

Technical information

Which is the right size?

Several sizes available:
S: between 1.50m and 1.64m
M: between 1.65 m and 1.74 m
L: between 1.75 m and 1.84 m
XL: between 1.85 m and 2.00 m

If you are between 2 sizes:
Choose the smaller size for easier steering (easier to handle) and comfort (straighter back).
Choose the larger size for easier pedalling with a more stretched-out position (position more suited to performance).


You have to pedal to go forward!
The electric assistance boosts your pedalling with its 250W motor, helping you ride over obstacles.
You'll get to enjoy longer MTB rides.
The motor stops providing electrical assistance when you stop pedalling.
The walking mode offsets the mountain bike's weight when you need to walk your bike.


Our team of mountain bike enthusiasts created this E-ST 100 electric mountain bike at our B'Twin Village in Lille, France.

We designed and tested the bike E-ST 100 MTB while involving riders at every stage of the project. We want you to have nothing but fun when you go mountain biking.


The frame of the Rockrider E-ST100 electric MTB is made of 6061 aluminium with hydroformed tubes. Why?
The battery sits snugly on the frame to make this electric MTB more sturdy.
The forged aluminium parts make it compatible with the new 27.5"+ tyre format (wider than the 27.5") in the rear, while remaining easy to manoeuvre. We've kept a frame geometry with short bases for easier steering.


The motor on the rear wheel was co-developed with VISION for mountain biking:
- a torque of 42Nm to overcome your first slopes
- a wheel axle of 150x12mm to stand up to rough terrain
- watertight bearings to withstand environmental conditions which can sometimes be tough.
What if you get a puncture? 8 Mm Allen key a needed to unscrew the wheel nuts. This tool is available in our 900 multi-purpose tool/bike multi-tool.


Our battery is equipped with SAMSUNG SDI cells, renowned for their high level of reliability and safety.
Our battery supplier sources its minerals responsibly and sustainably, and is part of the "Responsible Minerals Initiative".


Our Rockrider mountain bike team has designed a battery that locks in place with a simple lever. Child's play!
This locking system prevents the battery vibrating when riding on rough terrain.
There is also a lock in case you want to stop your battery getting stolen. For example, if you park your bike in the street.


A discreet LCD control screen. It is located just to the side of your left grip, so you can choose between the 3 assistance modes without letting go of the handlebars: (Deactivated), Economy, Standard, and Boost.
You'll also find a host of useful information:
-Current speed
-Average speed
-Maximum speed
-Distance covered
-Total distance
-Battery level
-Remaining battery range (in km)
-Active assistance mode


Mode 0 - Deactivated
The battery is not used.

Mode 1 - 20 to 100 W:
Extend your rides by preserving the battery. Ideal when you want a little push on small gradients.

Mode 2 - 80 to 175 W:
This is the most versatile mode. Climb your first slopes without getting too tired and without using too much power.

Mode 3 - 150 to 250 W:
Get the most out of your bike in the most demanding situations


Calmly overcome obstacles (roots, rocks, gravel, etc.) thanks to the 100mm of travel in the Suntour XCT 30 fork.

Its design, based on a mechanical spring, is reliable and easy to maintain.
It features U-Fit (weight adjuster) technology so that you can easily adjust the stiffness, based to the rider's weight, using a dial.


The E-ST100 electric bike is equipped with a single chainring and anti-drop technology to prevent chain drops.
A single shifter on the right handlebar makes it easy to shift between the 8 speeds.

In detail:
- Anti-derailment 32-tooth chainring
- MICROSHIFT M25 8-speed rear derailleur
- MICROSHIFT TS39 right shifter with indicator
- MICROSHIFT H081 8-cog cassette (11-34 teeth)
- KMC Z7 chain


These wheels were specially designed for this mountain bike:
- 23 mm rims (width between brackets), 28 spokes at the front and 36 oversize spokes at the rear, for greater durability and good grip on wide tyres (up to 2.5").
- Cone hub with bearings (easy to maintain) at the front
- Sealed motor bearings at the rear
- TUBELESS READY rims: you will need TUBELESS tyres, specifc PRESTA valves, and puncture sealant.


So you feel safe on any terrain, and for traction suited to your motor, the E-ST100 MTB is equipped with exclusive Rockrider All Terrain Light (30 TPI) tyres with a wide 2.2-inch cross-section. Our test riders particularly liked these tyres for their good grip Mounted on wide rims, these tyres, and the rubber they are made from, provide great grip, traction, and comfort. on any terrain.


No matter the riding conditions (dry, muddy, wet), the Tektro TKD68 180 mm mechanical disc brakes at the front and rear provide powerful, progressive braking.

Incompressible cable housing ensures a firm touch and perfect transmission of power from lever to disc.


The adjustable stem brings the E-ST 100 controls to your hands. The all-aluminium ROCKRIDER stem is 70 mm (size S), 80 mm (size M/L), or 90 mm (size XL) and can be raised to 5 adjustment intervals: + 0mm, + 7.5mm, + 15mm, + 22.5mm, + 30mm.
In detail:
- 720mm oversize ROCKRIDER SPORT aluminium handlebar
- ROCKRIDER SPORT "soft touch" ergonomic grips for good grip and a comfortable feel.


Since your mountain bike rides will get longer and longer, it is important to sit comfortably. So our teams designed the exclusive ROCKRIDER Ergofit Evo saddle.Suitable for all hip sizes, the "hammock" shape is particularly good for sporty rides.

The 31.6 mm aluminium seat post ensures compatibility with most adjustable and suspended saddles on the market.

Platform pedals

The bike comes with 520 GRIP MTB platform pedals (ref. 8487130) with a wider pedalling surface and more pronounced dots for better grip on the pedal.However, if you are looking for improved performance when pedalling and better control of the bike when cycling, we recommend replacing them with clipless pedals with platforms or wide aluminium platform pedals.


Your E-ST100 mountain bike is fitted with a bell, lights, wheel reflectors and pedals.

The frame is compatible with:
- front and rear mudguards
- stand
- bottle cage (on the horizontal tube)
- saddle pouch
- rear pannier rack (fixed onto the seat stays or special mounts for wide bikes, 150mm gap for the rear wheel)
- child seat


Tip no.1
When mountain biking, there is always the risk of a fall: don't forget to wear a helmet.

Tip no. 2
A puncture can happen at any time, so always remember to take a repair kit and an 8 mm Allen key for removing your rear motorised wheel.

Tip no.3
If you don't want to stop to drink, bring water in a bottle or water bladder to access it while riding.


To optimise the durability of the components, we recommend a maximum load of 120 kg (rider, kit + bike).
To find out more about usage and maintenance information of the Suntour fork, go to the Suntour website.
There you will be able to download the user manual for your fork.

Care advice

Leave your battery on the bike when washing using a hose. This will protect the connectors from rusting.


Lifetime (frame, stem, handlebar). Availability of spare parts: 2 years.Guaranteed for 500 charges.


22.5 kg
Weight without pedals.

Product concept & technology

Product Composition

Frame 100% Aluminium 6061


Store it in a warm, dry place away from corrosive products and salty air. Never store with the battery flat, and remember to recharge it at least once every six months.

User Directions

Don't forget to remove the battery to handle the chain.


Our engineers always have real riders test all our products in real conditions. These tests round out our lab tests and let us validate all our products before they hit store shelves.


To have more informations about this product, consult the notice


27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue
27.5" Electric Mountain Bike - Blue


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