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Rockrider ST100, Mountain Bike, 24'', Kids 4'5" to 4'11"

Sale price: $199.00 Regular price: $299.00

We've designed this robust, easy-to-use (1 chainring) 24-inch children's MTB for helping children to get started with mountain biking.

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Sale price: $199.00 Regular price: $299.00

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San Francisco, 735 Market St. Options

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Model: 8549161

Product Features

A photo of the Rockrider ST100, Mountain Bike, 24'', Kids 4'5" to 4'11" in use

Rockrider ST100, Mountain Bike, 24'', Kids 4'5" to 4'11" | 9- to 12-year-olds (4'5" to 4'11") wanting to start mountain biking.

We've designed this robust, easy-to-use (1 chainring) 24-inch children's MTB for helping children to get started with mountain biking.

Easy to use

Equipped with a grip shifter to easily change gears (6 speeds).

Brake control

2 V-Brake pads for effective braking.


Tires with side lugs for good grip in the turns.

Cycling comfort

A saddle with a sporty design, specially sized for children's build.

Product Lifestyle Image Gallery

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Rockrider ST100, Mountain Bike, 24'', Kids 4'5 

Rockrider ST100, Mountain Bike, 24'', Kids 4'5 

Rockrider ST100, Mountain Bike, 24'', Kids 4'5 

Rockrider ST100, Mountain Bike, 24'', Kids 4'5

Product Customer Reviews

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12 Reviews
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Rockrider ST100, Mountain Bike, 24'', Kids 4'5
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Pedal broke within a day

This looked like a great bike at first, but after my son rode it for a day, one of the pedals detached and we cannot screw it back in place (the thread is broken.) I contacted customer service, who promesses that the Cycling Manager would call me (they set up a meeting time with me), but no one called. We are very disappointed and do NOT recommend this bike. Customer service gets an F since they failed to contact us... Now we are stuck with a bike that’s useless...

Good bike

I lived in France and rode Rockriders. It's a good, solid bike. The brakes and derailer we're we'll set up on arrival. My only complaint is that it doesn't have a suspension fork.

Mountain Bike

Kids love it

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Dear Jamil, thank you for your time in leaving us with a 5-Star rating on our Rockrider ST 100 Kid's 9-12 years 24" mountain bike. We are glad that we managed to delight you with the standards of our product. We really appreciate your loyalty with Decathlon. Please let us know if there is anything else we can improve on in the future. Thank you once again for your time and we hope to serve you again soon!


Cycling To School

Very good

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Dear Customer, thank you for your time in rating our product/service. We are glad to know that you have enjoyed shopping with us. Thank you once again for your time and we hope to serve you again soon!

Nurul amera

Good entry-level bicycle.

This was a gift for our 10 year old son. Previously on training wheels, we used this bicycle to help him balance & ride solo. Amazingly enough, he was able to do so after the second practice. This bicycle was built well and I appreciate the guard-bar that protected the rear gears. He fell several times during practice with loads of dents/scratch-marks found on this piece that was protecting the gears. I do recommend this to other parents and I employ everyone to purchase online as delivery is provided. Aydin & his bike:

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Hello Rehman!

Thank you for the review for the Rockrider ST100 24" Mountain Bike.

This is a good kids' bike for beginners. Thanks to the sturdy steel frame and 6 speed grip shifter, the bike is built to be durable and changing gear is safer and easier for children! Yes indeed, the derailleur guard is effective in protecting the derailleur in the event the bike is dropped multiple times.

I hope you enjoy your purchase, stay safe and have a great day ahead! :)

Your coffee shop commuter


Before time delivery

Bought for my 8 year old son, 130cm tall. The item was delivered in good condition before the expected delivery date. But the cycle doesn’t come with a stand. Need to order that separately. Didn’t see such a clause in the description. Would be good to mention that.

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Hello Parvathi,

Thank you for submitting your review and suggestion for this Rockrider ST 100 Kids' 9-12 years 24" Mountain Bike!

Your feedback matters as it allows us to further understand how you use our products and online platforms and how we can improve to serve your needs better. Just to clarify, all our 20" and 24" kids bikes do not come with a side stand. There is also some information about the bike accessories included with this bike on the product page, under the sections "TECHNICAL INFORMATION" > "BIKE ACCESSORIES". This information can also be found under the "ASK A QUESTION" section, if you search for the keyword "stand".

Nevertheless, thank you once again for your feedback, our digital team will take note to make this information clearer and more accessible for all our customers in the future :)

We look forward to more of your reviews and sharing! In the meantime, keep sporting on, and we hope to see you in our stores soon! :)

Sport on safely!


Digital Interaction Relay

Junior Bicycle 24”

The only thing my son did not like was the grip shifter. It makes his palm quite painful after riding and the up shifting is not smooth. Otherwise, this is 100% worthy for entry level MTB.

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Hi Brandon,

Thanks for your honest opinion on the grip shifter  on the ST100 24" Mountain bike. Yes I agree that the supplied entry level grip shifter is stiff and not the easiest for kids to use. You could try our kid's gloves @ to add comfort to your son's palm.


Kid's Bike Sport Leader, Decathlon (Joo Koon)
New bike

Good value for the money. It works. My son is happy!

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Hi Robert

Thank you very much for sending me your reviews. I am so glad that you love our product and find it great for value!  I am happy that your son enjoys his bike too.

Keep your sharing coming.

Continue sporting and stay fit!

Worry Less Zumba More

Caroline Lee

Front Line Customer Service Adviser & Zumba Diva

Decathlon Joo Koon

Ligera y solida

Me parece que hice una muy buena compra para mi hija, hay más baratas en otros lados pero ésta es muy solida, ligera y cero ruidos. Estoy contento con lo que obtuve por lo que pagué.

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très belle expérience

excellent vélo, je le recommande vivement !!!

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สวัสดครับ คุณลูกค้า

ขอบคุณที่ไว้วางใจสินค้าของดีแคทลอนครับ และขออภัยที่เรายังไม่มีบริการนี้ครับ แต่ในตอนนี้คุณสามารถนำรถมาที่ศูนย์บริการใกล้บ้านได้ทุกสาขาเลยนะครับ


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Size Guide

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Additional Product Information


Bike frame

  • 100% Steel

A frame that is suitable for mountain biking

Our engineers have designed a new sturdy steel frame. The frame's rear chainstays are short, making the bike responsive and easy to handle.

Controlled braking

2 V-Brake pads for effective braking. These brakes are composed of calipers that exert more or less pressure on the rim to slow or stop the rotation of the wheels.

Changing gears (6 speeds)

This bike is equipped with a grip shifter to change between the 6 speeds: It's a safer and easier system for children so they don't need to let go of the handlebar. This makes changing gears to match the terrain simple and easy!

A reinforced, ergonomic saddle

A saddle with a sporty design, designed with care to adapt to the morphology of children. It is equipped with a plastic cover at the back (a bumper) to protect from any potential impacts.

Riding position

To provide you with maximum comfort, this mountain bike is equipped with a high-rise stem. Your position on the bike is slightly raised so you can better anticipate your trajectory.


The new chainset has a 152 mm crank that is designed for a child's leg length. This chainset allows you to start pedaling more easily. The double chain guard prevents the chain from derailing.

24" wheels and mtb tires

To transport the bike, we’ve made it easy to remove and attach the front wheel. It is equipped with a quick-release system. The tires are designed for mountain biking. The side lugs provide good grip for cornering. The recommended tire pressure is indicated on the side of the tire (2 to 3.5 bars). 24" inner tube, 1.7" to 2.2" Schrader valve.

Bike accessories

This MTB is equipped with a bell, lighting, wheel reflectors and platform pedals. The frame is also compatible with other B'Twin accessories: - front and rear mudguards; - stand; - bottle holder; - bike bags; - stabilizers

Dimensions of the bike ready to use

Length: 63". Height: 39.4". Width: 22".



Storage instructions

Store the bike in a clean, dry place. Clean and grease the chain regularly. Our tips for before each ride: inflate the tires to the pressure indicated on the sidewall.


for life (frame, stem, handlebars, rigid fork). Find out more about the bike guarantee.

Superior quality. Unbeatable prices.

For 40 years, Decathlon has delivered the best value in the retail sports industry by offering high-quality, sustainable and cost-effective products.

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