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ROCKRIDER ST 900 24''kids MTB 9-12 years Red



Delivery from thursday


Only 3 left in stock!

Sold by Alltricks


What size kid's bike do i need?

This handy chart should show you the right bike for your child, based on age, height and wheel size (inches). Bikes with 12" wheels are generally balance bikes: with no pedals or cranks, they are designed to teach balance and control and are the perfect introduction for young children up to 90cm.

Kid's bike sizing guide:

Wheel Size 10'' - 12.5'' 14'' 16'' 18'' 20'' 24''
Rider Height (cm) 85 - 95 95 - 105 100 - 115 110 - 125 120 - 135 130 - 155
Age Range 1.5 - 3 3 - 4 4 - 6 6 - 7 7 - 9 9 and +

All little riders grow at different rates. So the best way of finding the right size bike for them is to look at models in their age range and then match their height to the right bike. As a rule, it’s best to get your child to sit on a potential new bike and to check that they can touch the ground with both feet.

Still confused? Contact us.

Note : Please note that specifications are subject to change without notice, based on component availability and other factors.

This all terrain bike is designed for children aged 9 to 12 years (135,150 cm) wishing to improve the practice of mountain biking.

To attack obstacles with dynamism, we have equipped this 24 inch mountain bike with an aluminum frame to reduce the weight. Its suspension fork and disc brakes allow you to go everywhere.
  • Ease of use: aluminum frame and pedals for lightness. Quick release to remove the wheels.
  • Brake control: front / rear mechanical disc brakes: powerful braking in all conditions
  • Yield: suspension fork. Skinwall tires for more lightness, with lateral studs.
  • Riding comfort: sport saddle combined with an aluminum seatpost for more comfort

A framework adapted to the practice of mountain biking
Our engineers have designed a new aluminum frame. Solid, light and dynamic: it is suitable for overcoming all obstacles during your mountain bike outings.

Master braking
Brake effectively with mechanical disc brakes at the front and rear.
The disc brake acts on the wheel axle to deliver powerful braking in any condition (dry, wet, mud ...).

1x8 drivetrain
This bike is equipped with speed shifter that can be managed with your thumb and forefinger, to quickly switch between 8 gears. The 36-tooth chainring and the 11-34 cassette facilitate shifting and cover courses with leveling. With just one command, you stay focused on your trajectory.

The front suspension to dampen the aces of the field
Face new obstacles (roots, pebbles, stones, ...) In all safety thanks to the cushioning of the front fork. Suntour fork with 50 mm travel.

Riding comfort
A saddle, sporty design, designed by us to adapt the morphology of children. Combined with an aluminum seatpost (solid and flexible), it brings you even more comfort.

To refine your riding, we have mounted this mountain bike with a short aluminum stem (70mm) and an "oversize" handlebar 540 mm long. You are thus more precise and more efficient on turns.

Aluminum pedals
The new aluminum crankset has a crank length of 152 mm which is adapted to the child's leg length. This lightweight pedals makes it easier to get started.
The double casing which includes the chain prevents it from derailing.

Double wall rims and skinwall tires
The double-walled aluminum wheels are resistant and light.
To transport the bike, we made it easier to assemble / assemble the front and rear wheel. They are equipped with a quick release system.
The tires use skinwall technology. This process makes it possible to reduce their weight, thereby improving performance, grip and comfort.
24 inch tubes section 1,7 2,2, schrader valve. Pressure indicated on the sidewall of the tire (between 2 and 3.5 bars).

Bicycle equipment
This mountain bike is equipped with a bell, lights, wheel reflectors and flat pedals.
The frame is also compatible with other b'twin accessories:
- front and rear mudguards
- stand
- bottle holder
- bicycle bag

The dimensions of the bike ready to ride
Length: 160 cm.
Height: 100 cm.
Width: 60 cm.

The dimensions of the frame
Upper tube length: 479.3 mm
Seat tube length: 345 mm
Length of rear bases: 415 mm
Seatpost length: 370 mm
Steering angle: 68.2

Guarantee: Lifetime (frame, stem, hanger, rigid fork). Learn more about the bike warranty.
Weight: 12 kg



Gender Boy
Manufacturer Reference 2391250
Wheel Size 24''
Groupset Shimano Altus 8S
collection 2020
Age 9 - 12




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