Product Colors and Sizes
- Black Friday product
- New Deal product
- Cyber Monday product
- Clearance product
- Deal product
- Best Seller product
- Ecodesign product
- New product
- Staff Pick product
- In The News product
- Innovation product
- product
- Black Friday product
- New Deal product
- Cyber Monday product
- Clearance product
- Deal product
- Best Seller product
- Ecodesign product
- New product
- Staff Pick product
- In The News product
- Innovation product
- product
Btwin Rockrider ST100 Mountain Bike 20" Kids 3'11" to 4'5"
A sturdy, single-speed, 20" white bike that's simple to ride. Equipped with front and rear lights and a bell, it can be ridden around town as well as on trails.
Free shipping over $49
Final Sale: No returns or exchanges
Free returns
Free pickup
San Francisco, 735 Market St. Options
Select an available color and size to see options.
Product Features

Easy to learn
Single-speed, simple and efficient bike. Bike weight 24.3 lbs.
Bike safety
V-Brakes provide powerful and easy braking.
Lifetime warranty
B’Twin offers a lifetime warranty on the frame, stem, handlebar and rigid fork.
Questions & Answers
Look for product information, frequently asked questions, opinions...
Question:
Is the rear hub freewheeling or coaster brake?
Answer:
This bike uses a freewheel on the rear hub only
Don't see the answer you're looking for?
Product Customer Reviews
Be the first to leave a review
Additional Product Information
Composition
Bike frame : 100.0% Steel
Frame
The chainwheel anti-derailment device and low step-through frame make it easy to get on and off.
Accessories / equipment
Fully equipped for use on public roads (bell, reflectors).The rear derailleur guard protects the derailleur from damage in the event of an impact.
Origin
Imported
Law label information

Btwin Rockrider ST100 Mountain Bike 20" Kids 3'11" to 4'5"
Your location: City, ST
Please enter a valid city with state or zipcode. Example: San Francisco, CA or 94101
Order online for
Heavy products return policy
If you return a product you will receive a refund for the purchase price plus any applicable sales taxes, less any non-refundable charges.
Decathlon will cover all shipping costs associated with your return except for items excluded from our return policy such as bikes, basketball hoops, snowboards, surfboards, tents, and other larger / heavier items.
Return costs for heavy products:
Weight Thresholds | Shipping within California | Shipping outside of California |
---|---|---|
> 9 lbs | $20.00 | $25.00 |
> 30 lbs | $50.00 | $65.00 |
> 100 lbs | $100.00 | $125.00 |
> 200 lbs | $200.00 | $230.00 |
If you return a product at any of our store locations, we will gladly help you find the best alternative product or refund you on the spot.
