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
Rockrider Adult ST100 27.5 Mountain Bike
Comfort first: CGF frame with raised position, 80 mm suspension, Ergofit hammock saddle with Flex stem, 27.5" wheels (26" in XS") so you stay comfortable as you ride.
Free shipping over $49
Final Sale: No returns or exchanges
Free pickup
San Francisco, 735 Market St. Options
Select an available color and size to see options.
About this item:
- Cycling comfort: Enjoy: the high position (CGF frame), 80mm suspension, hammock saddle, flex stem
- Efficiency: Progress: light frame, 21 speeds, 27.5” double-walled wheels (26”1 wall in XS)
- Precision: Control your path with tires with side lugs and V-brakes.
- Lifetime warranty:Rockrider offers a lifetime warranty on the frame, handlebars, and stem.
Product Features
![A photo of the Rockrider Adult ST100 27.5 Mountain Bike in use](http://www.decathlon.com/cdn/shop/files/ZH_20ST_20100_20BLACK_208403062_20CN_20PSHOT_20001_20jpg_20_7C_20PSHOT_acb1f5ab-dd25-499c-9c9b-4d35bda8d23d.jpg?v=1700570940&width=500)
Cycling comfort
Enjoy: the high position (CGF frame), 80mm suspension, hammock saddle, flex stem
Efficiency
Progress: light frame, 21 speeds, 27.5” double-walled wheels (26”1 wall in XS)
Precision
Control your path with tires with side lugs and V-brakes.
Product Lifestyle Image Gallery
Image Gallery
![Rockrider Adult ST100 27.5 Mountain Bike, Image 1 of 8](http://www.decathlon.com/cdn/shop/products/ZH_20MTB_20beginner_20User_20Pic_208403062_208403010_208381864_20CN_20VSCENE_20001_20jpg_20_7C_20SCENE_bbd64612-818d-4229-bb11-6c3ef2a26950.jpg?v=1700570942&width=525)
![Rockrider Adult ST100 27.5 Mountain Bike, Image 2 of 8](http://www.decathlon.com/cdn/shop/products/ZH_20MTB_20beginner_20User_20Pic_208403062_208403010_208381864_20CN_20VSCENE_20001_20jpg_20_7C_20SCENE_9b04051d-bfb9-4815-9bec-1b79fc5b17f6.jpg?v=1700570942&width=525)
![Rockrider Adult ST100 27.5 Mountain Bike, Image 3 of 8](http://www.decathlon.com/cdn/shop/products/ZH_20MTB_20beginner_20User_20Pic_208403062_208403010_208381864_20CN_20VSCENE_20001_20jpg_20_7C_20SCENE_e8ec9eb8-4078-45ec-856d-ed781a01a7e2.jpg?v=1700570942&width=525)
![Rockrider Adult ST100 27.5 Mountain Bike, Image 4 of 8](http://www.decathlon.com/cdn/shop/products/ZH_20MTB_20beginner_20User_20Pic_208403062_208403010_208381864_20CN_20VSCENE_20001_20jpg_20_7C_20SCENE_70eeef0a-4c78-4e40-ae28-03eea0c08ce5.jpg?v=1700570942&width=525)
![Rockrider Adult ST100 27.5 Mountain Bike, Image 5 of 8](http://www.decathlon.com/cdn/shop/products/ZH_20MTB_20beginner_20User_20Pic_208403062_208403010_208381864_20CN_20VSCENE_20001_20jpg_20_7C_20SCENE_dd5de8b7-fbc5-4952-a3a9-3308d1adf17f.jpg?v=1700570942&width=525)
![Rockrider Adult ST100 27.5 Mountain Bike, Image 6 of 8](http://www.decathlon.com/cdn/shop/products/ZH_20MTB_20beginner_20User_20Pic_208403062_208403010_208381864_20CN_20VSCENE_20001_20jpg_20_7C_20SCENE_62b1c07f-dfb7-4990-9cad-35873b93b4d9.jpg?v=1700570942&width=525)
![Rockrider Adult ST100 27.5 Mountain Bike, Image 7 of 8](http://www.decathlon.com/cdn/shop/products/ZH_20MTB_20beginner_20User_20Pic_208403062_208403010_208381864_20CN_20VSCENE_20001_20jpg_20_7C_20SCENE_fda749ec-321d-40e3-90f7-917de8fe4a41.jpg?v=1700570942&width=525)
![Rockrider Adult ST100 27.5 Mountain Bike, Image 8 of 8](http://www.decathlon.com/cdn/shop/products/ZH_20MTB_20beginner_20User_20Pic_208403062_208403010_208381864_20CN_20VSCENE_20001_20jpg_20_7C_20SCENE_95ba8ede-f760-4412-a071-f0e13b0b6cfa.jpg?v=1700570942&width=525)
Questions & Answers
Look for product information, frequently asked questions, opinions...
Question:
Is the seat adjustable on this bike
Answer:
Yes, the seat can be adjusted in height with a quick release. No tool needed
Question:
What is the weight capacity for Large and XL bikes ?
Answer:
The maximum capacity is 140kg or 300 lbs.
Question:
I could see that this cannot be returned.But if there is a shipping or manufacturer defect how do I handle it...
Answer:
Please contact our customer service team at customer.service@decathlon.com or from our contact form page. To help start your claim we will need the following information: Customer name, USS order number, Item name and documentation (images/video) of the defect you have noted in your item. Please look to provide as much detail as possible, so our team can properly review your case.
Question:
decathlon bike st 100 had a flat tire today. both the tire and the inner tube are more like broken. Where can I find the manual for the Bike to get the information the tire and inner tube for replacement. I saw the tire said: 27.5x2.00 Thanks
Answer:
Indeed you can replace the tire with 27.5 x 2 to 27.5 x 2.5 tires. for the tube I recommend this size. https://www.decathlon.com/collections/bike-tubes/products/btwin-schrader-inner-tube-275-x-19-25-x-48mm-15167?variant=1518952448013
Question:
What is the inside front fork dimension? We're looking a roof racks and we need to know if we need adapters for a 100mm mount
Answer:
The measurement inside the fork, where the hub will be placed, is 100mm.
Question:
Is the bike true to size? For example is the small comfortable for a person at 5’4?
Answer:
Yes it is true to size. A small typically fits a person 5'1" - 5'5". Of course all people are build diffrently i.e long torso or legs - generally to sizing is accurate.
Question:
Does the bike have lights?
Answer:
This bike does not come with lights, they can be purchased seperately. The bike does come with reflectors.
Question:
What size should I order for my son? He is 6' and a half inch.
Answer:
XL will be the right size for him.
Question:
Does the bike come assembled? Does it need any additional parts to be purchased separately (like pedals) to start riding?
Answer:
This bike come 95% assembled, you will need to put on the front wheel and adjust the seat height. It does come with everything you need to ride it, including pedals. But a kickstand and waterbottle cages would be extra.
Question:
It shows shipping is 200$, can i pick it up from store?
Answer:
We do not have store in the U.S. but we offer a free pick up from our warehouse if you are in the Oakland CA area
Question:
Whats the box total weight and dimensions?
Answer:
It depends the model and size of the bike but assume 8" Thick 32" tall and 52" wide, weight boxed is aproxamately 40lbs
Question:
Do you sell the individual wheels? I need a replacement for the back wheel since I don’t have equipment to true the wheel
Answer:
No we do not, I would recomend going to your local bike shop. As they typically stock a wide variety of wheels
Question:
I am between 5'11 and 6'0. Which bike size should i purchase?
Answer:
A large should be a good fit for you
Question:
I am 6’2. Is XL good for me?
Answer:
yes - perfect
Question:
I am 6.2 feet tall. Would XL size be a good fit for me?
Answer:
yes - perfect
Question:
My rear tire went flat, ive tried removing the wheel and it wont budge, most youtube videos, including decathlons showcase rear wheels of different designs than this bike, where can i find a guide on removing it?
Answer:
Make sure you loose both bolts and slide the wheel forward, with the tire completely deflated. The design is standard. A Pro trick is to also shift the bike so the chain is in the small chain ring up front, and smalles gear in the back, putting the least amount of tention on the chain making the wheel much easier to remove.
Question:
Does it come with all the necessary accesories and guide to help assemble the remaining part of it?
Answer:
Yes, it does.
Question:
When will you have the medium size available?
Answer:
Unfortuanely not, we will not be stocking this model moving forward.
Question:
How much is the total weight including package and all, ready for shipping? I'd need to know this is to know if It can be shipped to my country or with that courier. Thank you
Answer:
40lbs.
Question:
Is it possible to change the brakes to disc brakes? on my own
Answer:
Unfortunately not. The frames and forks are specically designed and reinforced to accept Disc Brakes.
Question:
Is there any way to get free shipping? If the product is on sale?
Answer:
Unfortunately not... sorry.
Question:
Is the hub a freewheel or a cassette?
Answer:
This bike uses a 7 speed Freewheel.
Question:
Why is this item being labeled as a "kids" bike? I'm really confused. I don't know any kids that stand 6'5" in height riding a 27.5 inch bike? That's crazy, please help.
Answer:
Ha! you are 100% correct, our apologies. We have several similar junior models and the wording was not accurately updated. This is an adult bike.
Question:
Do you ship to Morocco?
Answer:
Not from the US but we have Decathlon Stores in Morocco.
Question:
What would the box size for a XL bike? I am trying to find out if I can pick up with my sedan
Answer:
It's 10'' wide x 35'' tall x 59'' long.
Question:
Do we need to buy the chain stay stand separately?
Answer:
Yes - A kickstand in not included with this bike.
Question:
It seems like only XL bikes are left. Can I ride it if I'm 5'10?
Answer:
Actually you can with this particular bike as they run small. Normally I would suggest a large, but with this particular model you will be fine with an XL.
Question:
Hi I need the full specks of my Rockrider ST100 sports Trail Bike where can I find the specs also I need to replace the chain there's is so many different chain specs , my bike is an XL Adult version Thanks
Answer:
Any 6/7/8 speed chain will work with your bike. You will need a chain tool to make it the correct legnth. I recomend taking it to a bike shop to have it done. Link to website for specs: https://www.decathlon.com/products/mtb-st100-rr-black-196952-192872?adept-product=mtb-st100-rr-black-196952-192872&variant=39456581320766&adept_product_id=mtb-st100-rr-black-196952-192872&source=search#product-information
Don't see the answer you're looking for?
Product Customer Reviews
Perfect for health walks.
Nice bike, has what it needs, used for a few months, no problems.
My son is very happy with it
Excellent bike. fairly light. solid. good position for a 177 cm tall person is the XL frame. Nice grips. Easy to change gears.
great
good quality at a good price
Very nice bike and very good quality price, very easy to change gears.
The bike has served me for a very long time. Initially for touring. Currently it is an "expedition" bike intended for trips with panniers. It has traveled thousands of kilometers with me.
Bike bought 2 years ago nothing wrong with it. My son is happy with it.
My son loves it
Top product
Perfect
Correct entry-level junior mountain bike, suitable for a beginner, however you quickly see the limits of the brakes which quickly become unadjusted and whistle as well as the transmission which is rather capricious after a few months of use. Nevertheless for the price... it's correct.
nickel
great bike for a school-age child, very nice colors of the bike, thanks to which the child is visible from a large distance, which I think affects the safety of traveling
Size Guide
![Size Guide Visual](http://www.decathlon.com/cdn/shop/files/sizechart-mountain-bikes_300x.jpg?v=15800566165677730642)
Additional Product Information
Composition
Bike frame : 100.0% Aluminum
A unisex sport bike
Available in a variety of sizes (XS: 4 ft9 Inch ~ XL: 6 ft7 Inch), the CGF frame is lightweight, comfortable, and versatile
How to choose the size of your bike?
S: 5 ft1Inch ~ 5 ft5Inch M: 5 ft5Inch ~ 5 ft9Inch L: 5 ft9Inch ~ 6 ft
Front shock absorber
The 80 mm SUNTOUR XCT front shock absorber is designed for rugged pavements, helping beginners easily cope with sporty bike rides. Mechanical springs are designed to be reliable and easy to maintain.
Transmission system
3 x 7 speed sprocket, 21 speed! Three-chain sprocket wheel (22/32/42 teeth) + grease protection - Microshift front derailleur - Microshift rear derailleur - with speedometer Microshift hand shift lever- 7 gears, 14~28 teeth Shimano sprocket
Horizontal / handle / handle
The ST100 sport bike has a 10° angled handle for a higher operating position and is easy to operate and comfortable.
Storage instructions
After washing, rub with a dry cloth to remove all traces of moisture.Store your bike in a cool, dry place, away from corrosive products and salty air.
Guarantee
Lifetime on frame and rigid fork. 2 years on parts.
Origin
Imported
Law label information
![](https://cdn.shopify.com/s/files/1/1752/4727/products/8bdfc1a5-64b0-409c-bffd-80152d762d79_100x.jpg)
Rockrider Adult ST100 27.5 Mountain Bike
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.
![Size Guide Visual](http://www.decathlon.com/cdn/shop/files/sizechart-mountain-bikes_300x.jpg?v=15800566165677730642)