Decathlon Rockrider ST50 21 Speed Aluminum Mountain Bike


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Aluminum Mountain Bike for sale at very affordable and competitive prices. Get a hitch free fast delivery from Mayer Sport Store.
Ready to go onto the bike trails and need a Mountain Bike that is suited right for you? Our Decathlon Rockrider ST50, 21 Speed Aluminum Mountain Bike, 26″, Unisex, Black, Small is designed for your first mountain bike ride in dry weather for up to 1 hour and 30 minutes. Recommended Small Bike height S: 5’1″ – 5’5″. The Mountain Bike has a total of 21 speeds, making it faster with smoother transitions and pedaling. Riding comfortably is crucial, the Bikes frame position is raised having your back straight at all times. Having responsive brakes is key for a safe ride. The Bikes aluminum brake level design allows braking with only two fingers. Riding Mountain Bikes for beginners may be uncomfortable riding for long periods. Our Bike has an ERGOFIT saddle that is wide and has a shape of a hammock. With a tire size of 26″, the tires will absorb any vibrations or shocks whenever riding over any trail. The Bike frame can hold a bottle cage, saddlebag, mudguard, stand, and pannier rack. We offer a lifetime warranty on the Bike’s frame, stem, and handlebar. This Bike does not come included with a Kickstand or a Bottle cage.
  • 100% aluminum: the frame of the Rockrider ST 50 mountain bike has been designed in aluminum to combine strength and lightness. Thus, your pedaling is more efficient.
  • Its “sloping” type geometry makes it easier to step over for both men and women.
  • The 80mm front suspension lets you overcome your first obstacles with peace of mind on slightly uneven trails. Its mechanical spring is a guarantee of reliability. Above all, the fork is easy to maintain.
  • This mountain bike has no rear suspension. It is a so-called “semi-rigid” mountain bike: ideal for starting and getting started on your first mountain biking tours.
  • Faced with a “full suspension” mountain bike (with a rear suspension), the interest is simple: the mountain bike is lighter; you lose less energy on flat ground.
  • 3 plates of 7 speeds, 21 speeds!
  • 2 rotating handles that are easy to handle.
  • On the left (trays): you manage the ascent/descent.
  • Right (speeds): you adapt your effort more precisely.
  • Triple chainring 22, 32, and 42 teeth + protection against grease.
  • MICROSHIFT FD-M20 front.
  • Derailleur -MICROSHIFT RD-M25.
  • Rear derailleur -MICROSHIFT MS25 revolving handles, with speed indicators.
  • SHIMANO 7-pinion cassette 14 to 28 teeth TZ500
  • Wide and solid chain KMC Z51.
  • The saddle attachment (welded) of the ST 50 prevents any movement of the saddle during your ride. And because your comfort is our priority, we offer you an exclusive ERGOFIT saddle, wider, with a profile in the shape of a “hammock”.
  • Easily adjust your saddle height with the 350mm long, 29.8mm diameter steel MTB seat post.
  • Brake effectively thanks to the 2 V-Brake type pad brakes. These brakes are made up of 2 calipers equipped with pads that exert a more or less strong pressure on the rim to slow down or stop the rotation of the wheels.
  • Thanks to the specific design of the ST 50’s aluminum brake levers, only two fingers are sufficient to brake.
  • With its lightweight 26-inch single-wall wheels, you can easily get started on mountain biking trails. DRY 26 x 2.0 tires are the most suitable for hiking on dry terrain. The central part is very rolling, while their side crampons provide good grip in turns.


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Comfort, Durability









Assembled Product Dimensions (L x W x H)

69.00 x 25.00 x 49.00 Inches

Warranty information

Lifetime warranty on manufacturing defects for all metal frames, rigid forks, stems, and handlebars 5 years warranty on all carbon frames and forks 2 years warranty on all other parts Excludes damages arising from normal wear and tear, misuse, negligence, and unauthorized modifications


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