ST 120 RR Vermilion

Ref. : 8520407

Mountain bike beginner

Easy to use/Comfortable

Color: vermilion red

  • S - 155-164CM undefined
  • M - 165-174CM undefined
  • L - 175-184CM Out of Stock

Our services :

  • Free delivery for Decathlon brands orders above $399
  • All Decathlon products are eligible for lifetime return

Products benefits

Cycling comfort


Brake control



1by system

Easy assembly / dismantling

easy to use and adjust

Shock absorption

80mm travel suspension fork


ST 120 RR Vermilion
ST 120 RR Vermilion
ST 120 RR Vermilion
ST 120 RR Vermilion
ST 120 RR Vermilion
ST 120 RR Vermilion
ST 120 RR Vermilion
ST 120 RR Vermilion

Technical information

This Rockrider ST120 has a history

Entirely designed and developed in France at the B'Twin Village (Lille), this mountain bike is the fruit of the work of an expert team of passionate mountain bikers.
To best meet the need for comfort and ease expressed by beginner mountain bikers, the team created, designed, and tested the ST120, involving riders at every stage of the project.
Whether you're heading out alone, with friends or family, the fun of riding the ST120 mountain bike has been fully approved by users!

MTB beginner

1x9 Transmission
Disc brake

How to choose the size

Several sizes available: XS: between 1.45m and 1.54m
S: between 1.55m and 1.64m
M: between 1.65m and 1.74m
L: between 1.75m and 1.84m
XL: between 1.85m and 2.00m


Because we've noticed that it's not always easy to get the right position on a mountain bike, our designers have created an entirely new frame that's easy to get onto for both men and women.
The CGF frame (Comfort Geometry Frame) is 100% aluminium for optimal comfort and excellent manoeuvrability. The slope angle has been designed to keep your back straight whilst the low rear ensures the bike is very agile when turning.

1x transmission

1x transmission

Disc brake

Disc brake


Slow down without worrying about obstacles: small rocks, cracks, holes and bumps!The wheels of the ST120 are tolerant and robust, with 27.5-inch double-walled 28-spoke rims (26-inch single-wall 32-spoke on the XS size).


Your ST120 mountain bike is delivered with a derailleur guard, chainwheel guard (to prevent your clothes becoming dirty), bell, lights, wheel reflectors and pedals.
The frame is compatible with:
-Front and rear mudguards (Flash MTB or MTB 900)
-Stand (500 Adult Base)
-Bottle cage
-Saddle pouch
-Rear pannier rack
-Child seat (Polisport Groovy frame mounted)

comfort and safe

We recommend that beginners wear cycling shorts with a pad (foam in the shape of a saddle) or a gel saddle cover to reduce soreness.

For longer rides, remember to take something to drink (e.g. a water bladder or bottle).

In all circumstances, even for a short ride, wearing a helmet is essential!


Frame: Lifetime warranty

Product concept & technology

Product Composition

Bike frame 100% Aluminium


After washing, rub with a dry cloth to remove all traces of moisture.
Store your mountain bike in a cool, dry place, away from corrosive products and salty air.

User Restrictions

Not suitable for XC, All Mountain, Enduro, BMX.


To increase the level of comfort, we also recommend that beginners wear cycling shorts with a protective pad and / or a gel saddle cover.

User reviews

Questions & Answers