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ROCKRIDER E-ST 100 Electric Mountain Bike, Blue - 27.5"

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was £799.99 -%


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£799.99 -%
This price includes a recycling fee for electrical equipment and batteries DecathlonDeeeTaxMentionAfterPrice / Since

* From To

* Sales from to Until end of stock
* From and limited stock
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This 27.5" electric MTB (EAMTB) is designed for MTB rides with lots of climbs and descents. With the E-ST 100 electric mountain bike (EAMTB), enjoy (or relive) your first MTB thrills. The smart electric assistance, driven by a cadence sensor and a control screen, helps you find your pace.
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Product benefits

Power Overcome any slope with the motor's torque of 42Nm at 250 W.
Autonomy Enjoy an average of 2-1/4 hours of biking thanks to a 380Wh 36V 10.5Ah motor.
Smooth pedalling Enjoy/relive your first MTB rides: smart help with cadence sensor
Cycling comfort Enjoy touring: raised position, 100mm suspension, Ergofit hammock saddle
Directional control Control your trajectory: all-terrain tyres, wide handlebar.

Technical Information


Several sizes available:
S: between 1.50m and 1.64m
M: between 1.65m and 1.74m
L: between 1.75m and 1.84m
XL: between 1.85 m and 2.00 m
If you are on the limit 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 improve the robustness of this electric mountain bike.
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 any slope
- a 150x12mm hub to stand up to rough terrain
- and sealed bearings to withstand the weather, which can often be tough when mountain biking.
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 stops the battery getting shaken when you go adventuring 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. The screen is right next to your left grip so you don't have to let go of the handlebar to choose from the 3 assistance modes available: (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. A perfect helping hand for small gradients.
Mode 2 - 80 to 175 W:
This is the most versatile mode. Climb any slope 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 XCR 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 ChainFlow 3D anti-slip technology to prevent the chain from derailing.
A single shifter on the right handlebar makes it easy to shift between the 8 speeds.
In detail:
- ChainFlow anti-derailment 33-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, 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.


The E-ST100 electric bike comes with ROCKRIDER Flat MTB platform pedals. The pedal surface is wider and the dots more pronounced to better keep the foot on the pedal.


Your E-ST100 mountain bike is supplied 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 motorised rear 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 ensure components last longer, we recommend a maximum load of 120 kg (rider and MTB included).
To find out more about usage and maintenance information of the SUNTOUR fork, go to the SUNTOUR website.
From there, you will be able to download the instructions manual for your component.


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


S - 150-164cm: 22.5 kg
M - 165-174cm: 22.5 kg
L - 175-184cm: 22.5 kg
XL - 185-200cm: 22.5 kg
Weight without pedals.

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Composition / advice

100.00% Aluminium 6061
Stock advice Store it in a cool, 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.
Restricted use : Don't forget to remove the battery to handle the chain.
instructions To get more information about this product, please read instructions
Legal notice To ensure components last longer, we recommend a maximum load of 120 kg (rider and MTB included).
To find out more about usage and maintenance information of the SUNTOUR fork, go to the SUNTOUR website.
From there, you will be able to download the instructions manual for your component.
How to choose your product

Our commitments

Test Product 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.
Guarantee : Lifetime (frame, stem, handlebars). Availability of spare parts: 2 years.Guaranteed for 500 charges.


Q : How to assemble your bike?
Everything you need to know about making sure your bike is comfortable, secure and ready to ride.
Q : How do you adjust your brakes?
Having properly functioning brakes is vital when out on the road. Check out how to get them working to your liking.
Q : How to replace a brake lever on a bike?
Having properly functioning brakes is vital when out on the road. Here’s a video to show you how to make sure your new brake level is working nicely.
Q : How to replace a disc brake?
Having issues with your disc brake? Then this video is for you.
Q : How to adjust your bike handlebar?
A suitable handlebar height is essential to your cycling safety and comfort. Find out how to adjust it to your liking with our video.
Q : Do you offer a Cycle To Work scheme?
Find out everything you need to know about way of getting to work that’s good you and the environment.Check Here

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E-ST 100 Electric Mountain Bike, Blue - 27.5
Maintenance and repair
Maintenance and repair
Spare parts