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Btwin Mountain Bike 27.5" Rockrider ST 100

Sale price: $99.00 Regular price: $399.00

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

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Size: Select a size
Size Guide
Sale price: $99.00 Regular price: $399.00

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Final Sale: No returns or exchanges

See our return rules for heavy items

Free pickup

San Francisco, 735 Market St. Options

Select an available color and size to see options.

Model: 8628165

Product Videos

Product Features

A photo of the Btwin Mountain Bike 27.5" Rockrider ST 100 in use
A photo of the Btwin Mountain Bike 27.5" Rockrider ST 100 in use

Btwin Mountain Bike 27.5" Rockrider ST 100 | http://s3-eu-west-1.amazonaws.com/spid-media-cloud/packshot/61/64/616432d0-d3ed-4e48-8173-b18a40167c96.jpg

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

Cycling comfort

Enjoy: the high position (CGF frame),80 mm 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

Easy to use

Change speeds quickly thanks to the grip shifters

Lifetime warranty

Rockrider offers a lifetime warranty on the frame, handlebars and stem

Product Lifestyle Image Gallery

Image Gallery



Btwin Mountain Bike 27.5 

Btwin Mountain Bike 27.5 

Btwin Mountain Bike 27.5 

Btwin Mountain Bike 27.5 

Btwin Mountain Bike 27.5 

Btwin Mountain Bike 27.5 

Btwin Mountain Bike 27.5 

Btwin Mountain Bike 27.5 

Btwin Mountain Bike 27.5

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

By Olivier on May 19, 2023 | STAFF

Question:

What is the weight capacity for Large and XL bikes ?

Answer:

The maximum capacity is 140kg or 300 lbs.

By Olivier on June 2, 2023 | STAFF

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.

By Ashley on May 19, 2023 | STAFF

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

By Olivier on June 22, 2023 | STAFF

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.

By Nicolò on July 10, 2023 | STAFF

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.

By Thierry on July 28, 2023 | STAFF

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.

By Thierry on July 28, 2023 | STAFF

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.

By Yann on Aug 8, 2023 | STAFF

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.

By Thierry on Aug 15, 2023 | STAFF

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

By Thierry on Aug 28, 2023 | STAFF

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

By Thierry on Sep 18, 2023 | STAFF

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

By Thierry on Sep 26, 2023 | STAFF

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

By Thierry on Oct 5, 2023 | STAFF

Question:

I am 6’2. Is XL good for me?

Answer:

yes - perfect

By Thierry on Nov 27, 2023 | STAFF

Question:

I am 6.2 feet tall. Would XL size be a good fit for me?

Answer:

yes - perfect

By Thierry on Nov 27, 2023 | STAFF

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.

By Thierry on Nov 27, 2023 | STAFF

Question:

Does it come with all the necessary accesories and guide to help assemble the remaining part of it?

Answer:

Yes, it does.

By Thierry on Dec 20, 2023 | STAFF

Question:

When will you have the medium size available?

Answer:

Unfortuanely not, we will not be stocking this model moving forward.

By Thierry on Dec 26, 2023 | STAFF

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.

By Thierry on Dec 26, 2023 | STAFF

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.

By Thierry on Jan 4, 2024 | STAFF

Question:

Is there any way to get free shipping? If the product is on sale?

Answer:

Unfortunately not... sorry.

By Thierry on Jan 19, 2024 | STAFF

Question:

Is the hub a freewheel or a cassette?

Answer:

This bike uses a 7 speed Freewheel.

By Thierry on Feb 6, 2024 | STAFF

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.

By Thierry on Mar 4, 2024 | STAFF

Product Customer Reviews

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10415 Reviews
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Btwin Mountain Bike 27.5
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Very good product

My son is delighted

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So far I am satisfied!

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Easy to use

Easy to use

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It's too early to say

I bought this bike for my son through the buy back program which went "excellent", i.e. I TOOK A BIKE FOR 6 MONTHS USED 4-6 TIMES BY MY SON THEN DECIDED TO CHANGE IT BECAUSE he grew 24 cm in 6 months. On the recommendation of the Decathlon Sibiu staff, I chose this model (the old bike was Atala size 24) and switched to this ST 100 model. I can say that I was satisfied with the service staff who valued the old bike at 60% of its new value and mounted the support from the old bike on the new one. At home I paid with the 3 vouchers, 2 from the buyback and one that I had in my account, I was satisfied that I only paid the difference. When I got home, I noticed in the Decathlon account that I had been billed for a new bike bottle holder that I didn't buy, I just asked the service guy to take it off the bike which I brought for buyback and to put on the new one. It seemed out of place to bill me for a new one if I knew I was installing it at home. I will give the notes for the product after 1 week of use if it is still possible

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I am extremely satisfied

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Very nice bike,…

Very nice bike, good quality, good value for money. Very good inertia when pedaling more, very very little rolling resistance which allows you to go faster, further, without pedaling!

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THANKS

THANKS

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Fishing equipment purchases

Always happy

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top

Super good purchase very happy

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Alright

Alright

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Great

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Balance price quality

No

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The bike is not ready to ride, missing a stand and mudguards

After delivery, the bike did not change the front gears properly, it was impossible to put the third gear in. I managed to adjust it after 10 attempts, but it was not without some nerves. The saddle is not suitable for riding, it is so hard that after 20 km the next day you can no longer sit on the seat because the pain is unbearable. I DO NOT RECOMMEND!

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Bicycle

I bought it for my son as a gift and he loved it.

Bought this bike last year hoping I would have better luck with service. One week after buying it had it into the store to have it looked at as the breaks were sticking and then gears were not shifting properly. Was told that all was well and it was shifting properly. Took to another shop and had the shifters replaced with micro shifters and tuned properly. Going back to that same shop to have the breaks redone here shortly. For price better than other bikes reliability meh.

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Size Guide

Size Guide Visual

Additional Product Information

Composition

Bike frame : 100.0% Aluminum

This rockrider st100 has a history

This mountain bike was fully designed and developed at the B'Twin Village (Lille, France) and is the brainchild of an expert team of mountain bike enthusiasts.To best meet the need for comfort and ease expressed by beginner mountain bikers, the team created, designed, and tested the ST100, involving riders at every stage of the project.Whether you're heading out alone, with friends or family, the fun of riding the ST100 mountain bike has been approved by users!

A unisex mountain bike

The ST100 mountain bike is suitable for both men and women.Carefully designed down to the smallest detail, with a noticeable slope on the top tube, with a wide range of sizes (XS: 4 ft9Inch to XL: 79Inch), the CGF frame of the ST100 is light, comfortable, and very versatile.To make the most of the improved comfort, the women of the Rockrider team recommend the 500 Women fts Sport saddle that is adapted to women fts morphology.

How do you choose the right st100 mountain bike size?

Several sizes available:XS: between 4 ft9Inch and 5 ftS: between 5 ft and 5 ft5InchM: between 5 ft5Inch and 5 ft9InchL: between 5 ft9Inch and 6 ftXL: between 6 ft and 6 ft6Inch

A light, comfortable, fun frame

Because we've noticed that it's not always easy to get the right position on a mountain bike, our designers have created an entirely new frame that's easy to get onto for both men and women.The CGF frame (Comfort Geometry Frame) is 100% aluminum for optimal comfort and excellent maneuverability. The slope angle has been designed to keep your back straight while the low rear ensures the bike is very agile when turning.

Front suspension for cushioning lumps and bumps

The SUNTOUR XCT 80 mm front suspension is designed for slightly uneven trails and helps you overcome your first obstacles with no worries.Its design, based on a mechanical spring, is reliable and easy to maintain. You can also easily adjust the stiffness using a dial.

Product testing

To increase the level of comfort, we also recommend that beginners wear cycling shorts with a protective pad and / or a gel saddle cover.

Storage instructions

After washing, rub with a dry cloth to remove all traces of moisture. Store your mountain bike in a cool, dry place, away from corrosive products and salty air.

Origin

Imported

 

Size Guide Visual

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