27.5+ Inch WOMEN’S ELECTRIC MOUNTAIN BIKE ROCKRIDER E-ST 900

This mountain bike has been designed and developed specifically to fit the female build. It is best suited to touring rides lasting 1.5 to 3 hours.With the E-ST900 electric mountain bike, there are no more limits to your rides. Power over any obstacle thanks to the motor’s 70 Nm torque, and enjoy longer rides with the 500 Wh battery.

IS ELECTRIC MTB A SPORT?

You have to pedal to go forward!
Electric assistance gives you up to 320% more pedalling power to get through obstacles, enjoy your mountain bike rides for longer, and help slower riders keep up in a group.
The motor stops its electrical assistance when you stop pedalling.
The walking mode compensates for the weight of the bike when you need to put your feet down.

Which is the right size?

Several sizes available:
S: between 1.50m and 1.64m / 21.9kg
M: between 1.65m and 1.74m / 22.1kg
L: between 1.75 m and 1.84m / 22.2kg

If you are on the limit between 2 sizes:
Choose the smaller size for easier steering (easier to handle).
Choose the larger size for easier pedalling and comfort (straighter back).

A word from the team

Our team of mountain bike enthusiasts created this E-ST 900 electric mountain bike at our B’Twin Village in Lille, France.
We designed and tested the E-ST 900 MTB by involving MTB riders at every stage of the project.

A FRAME FOR STURDINESS AND FUN

The frame of the Rockrider E-ST900 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.

MOTOR WITH 70NM TORQUE

The BROSE T Aluminium central motor is specially designed for mountain biking:
– 70 Nm torque to handle large obstacles and steep gradients
– metal housing for maximum durability
– belt for an ultra-quiet motor
– sealed bearings to hold up to tough environments while mountain biking

A BATTERY WITH SAMSUNG CELLS

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”.

A battery that’s easy to lock

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 simple, ergonomic control screen

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 4 assistance modes available: Deactivated, Economy, Standard, and Boost.
You’ll also find a host of useful information:

Assistance level
Battery level
Speed (current, average, maximum)
Remaining battery life
Distance covered (total and trip)

4 assistance modes for any situation

Mode 0 – Deactivated
The battery is not used.

Mode 1 – Economy +40%:
Extend your rides while conserving battery life. Ideal when you want a little push on small gradients.

Mode 2 – Economy +80%:
Gain power. A perfect helping hand for keeping up with other mountain bikers.

Mode 3 – Standard +160%:
This is the most versatile mode. Climb any slope without getting too tired and without using too much power.

Mode 4 – Boost +320%

ROCKSHOX FRONT SUSPENSION TO MAINTAIN CONTROL AND ABSORB BUMPS FROM ROUGH TERRAIN

Ride over obstacles (roots, pebbles, stones, etc.) easily thanks to the Rockshox JUDY fork with 120 mm of travel.
This fork has:
– a thru axle and conical pivot for more durability.
– pneumatic spring for optimal adjustment based on your weight
– rebound adjustment and lockout for better control, depending on the terrain.

SINGLE CHAINRING DRIVETRAIN

The E-ST900 electric bike is equipped with a single chainring and ChainFlow 3D anti-drop technology to prevent chain drops.
A single shifter on the right handlebar makes it easy to shift between the 10 speeds.

In detail: – ChainFlow anti-derailment 34-tooth chainring
– SHIMANO DEORE M6000 Shadow+ 10-speed rear derailleur with long cage
– SHIMANO DEORE M6000 right shifter
– SHIMANO DEORE 10-cog cassette (11-42 teeth)
– KMC E10 Turbo special e-bike chain

27.5+ Sunringle Duroc 40 Wheels

These wheels were specially designed for this mountain bike:
– 36 mm rims (width between brackets) and 32 spokes at the front and rear for greater durability and a good hold on wide (2.8″) tyres.
– BOOST format thru axles (12x148mm rear, 15x110mm front) for greater stiffness
– Aluminium hubs with sealed bearings.

– TUBELESS READY rims: you will need TUBELESS tyres, specific Presta valves, and puncture sealant.

HUTCHINSON TYRES

So you feel safe on any terrain, and to provide traction suited to your motor, the E-ST900 mountain bike is equipped with Hutchinson Taipan Koloss 27.5+ tyres with a 2.8″ cross-section. Our test riders particularly liked these tyres for their grip on the ground. Mounted on wide rims, these tyres provide great grip, traction, and comfort on any terrain.

180MM DOUBLE HYDRAULIC DISC BRAKES: GET A GRIP ON YOUR BRAKING

No matter the conditions you ride in (dry, muddy, wet), the Tektro TKD32 hydraulic disc brakes on the front and rear provide powerful, progressive braking. Oversized 180mm diameter discs provide even more power.

HANDLEBAR, STEM, GRIPS: TAKE CONTROL OF THE HANDLEBARS

With its adjustable stem, the E-ST900 controls are close to hand. The all-aluminium B’Twin stem is 60 mm (size S/M/L) and can be raised using 5 adjustment intervals: + 0mm, + 7.5mm, + 15mm, + 22.5mm, + 30mm.

In detail:
– Narrow 680 mm-wide aluminium handlebars for women
– Ergonomic, lock-on B’Twin Sport Comfort grips for good grip and a comfortable feel.

ERGONOMIC WOMEN’S SADDLE: COMFORTABLE AND SPORTY SEAT

Since your mountain bike rides will get longer and longer, it is important to have a suitable seat designed for women’s hips. Our teams have designed an ergonomic saddle which is hollow in the centre to prevent chafing and enhance comfort.

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.

Accessories

Your E-ST900 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, 148 mm gap for the rear wheel & 2.8″ fat tire)
– child seat
…

OUR ADVICE FOR YOUR FIRST RIDES

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 could happen at any time, so always remember to take a repair kit and a 6 mm Allen key for removing your wheels.

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.