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Mongoose

Mongoose Flatrock Mountain Bike, 24, 26 or 29 Inch Bike for Youth and Adults, 7 or 21 Speed, Aluminum Frame, Suspension Fork, Twist Shifters, Linear Pull Brakes, for Adults, Boys and Girls

  • Based on 397 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Thursday, Sep 11
Order within 13 hours and 45 minutes
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Color: Mint


Size: 14.5-Inch Frame/24-Inch Wheels


Features

  • ADULT AND YOUTH MOUNTAIN BIKE: Hit up the trails with the Flatrock by Mongoose. Featuring 24, 26 or 29-inch wheels, this bike is perfect for riders from 4'4" - 6'0" tall. Built for adult and youth riders, this bicycle brings everyone in on the fun.
  • BORN IN DIRT: From singletrack to crushed gravel paths, the aluminum mountain frame is built for adventure. With a sloping top tube, this adults, girls and boys mountain bike offers a modern look.
  • BUILT FOR ADVENTURE: This Mongoose bike is ready to roll with knobby mountain tires for superior grip and stability. The suspension fork absorbs bumps and uneven terrain, ensuring a smooth, controlled ride.
  • SHIFT INTO GEAR: This 21 or 7-speed bike features twist shifters for smooth transitions and the right gear for climbs and descents. Linear pull brakes provide reliable stopping power, giving riders control on varied terrain.
  • KNOW YOUR ROOTS: As one of the OGs in BMX and action sports, Mongoose has helped bring this movement to the world. For over 50 years, we've been all about epic rides and pushing limits and we're just getting started.

Description

Adventure starts where the pavement ends with the Mongoose Flatrock, an adults or kids mountain bike built for all-terrain fun. With 24, 26 or 29-inch wheels, this adults and boys and girls mountain bike is ideal for riders between 4'4"" - 6'0"", perfect for bringing explorers into the action. Its knobby mountain tires with an improved tread pattern provide superior traction and stability. The aluminum mountain frame is easy to handle while offering a clean look with its sloping top tube. Equipped with twist shifters, this 21 or 7-speed bike ensures smooth shifting and the right gear for tackling hills and descents. Linear pull brakes provide reliable stopping power, keeping riders in control on paved, dirt and crushed gravel terrain. Whether taking on the trail or cruising the neighborhood, the Flatrock is ready for the adventure. Assembly is easy with a few common household tools and the included instruction guide. At Mongoose, we know our roots – as pioneers in BMX and action sports for over 50 years, we're dedicated to delivering an epic ride every time. Get ready to push the limits

Bike Type: Mountain Bike


Age Range (Description): Youth


Brand: Mongoose


Number of Speeds: 7


Color: Mint


Wheel Size: 24 Inches


Frame Material: Aluminum


Suspension Type: Front


Special Feature: Adjustable Seat, Durable, Multi-Speed, Quick Release Seat


Included Components: Kickstand, Mountain Bike, Reflectors


Bike Type: ‎Mountain Bike


Age Range (Description): ‎Youth


Brand: ‎Mongoose


Number of Speeds: ‎7


Color: ‎Mint


Wheel Size: ‎24 Inches


Frame Material: ‎Aluminum


Suspension Type: ‎Front


Special Feature: ‎Adjustable Seat, Durable, Multi-Speed, Quick Release Seat


Included Components: ‎Kickstand, Mountain Bike, Reflectors


Size: ‎14.5-Inch Frame/24-Inch Wheels


Brake Style: ‎V Brake


Wheel Width: ‎2.3 Inches


Specific Uses For Product: ‎Trail


Item Weight: ‎33.2 Pounds


Style: ‎Mountain


Model Name: ‎Flatrock


Power Source: ‎Pedal Power


Wheel Material: ‎Aluminum


Year: ‎2025


Seat Material Type: ‎Plastic


Warranty Type: ‎Limited


Maximum Weight Recommendation: ‎33.18 Pounds


Assembly Required: ‎Yes


Bicycle Gear Shifter Type: ‎Twist Grip


Is Autographed: ‎No


Number of Handles: ‎2


Skill Level: ‎Beginner


Minimum User Height: ‎52 Inches


Derailleur Configuration: ‎Rear


UPC: ‎038675287976


Bicycle Drivetrain Type: ‎Derailleur


Manufacturer: ‎Pacific Cycle, Inc.


Item Package Dimensions L x W x H: ‎50 x 26.1 x 10 inches


Package Weight: ‎17.69 Kilograms


Item Dimensions LxWxH: ‎64.37 x 26.77 x 36.22 inches


Brand Name: ‎Mongoose


Warranty Description: ‎5 year limited warranty on frame. 1 year limited warranty on parts. 30 day limited warranty on wearable parts.


Material: ‎Steel


Number of Items: ‎1


Part Number: ‎M2897G25F1OS


Date First Available: October 28, 2024


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Thursday, Sep 11

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • My Go-To for Fun and Adventure!
If you're looking for a bike that's ready for anything, whether it's cruising around the neighborhood or hitting some easy trails, the Mongoose Flatrock is an awesome choice. I've been riding mine, and it's just a fantastic, reliable bike that makes getting out and about a joy. First off, it's really comfortable to ride. The front suspension (that's the "hardtail" part, meaning suspension in the front fork) does a great job soaking up bumps and uneven paths, so your arms and body don't take a beating. This makes longer rides or slightly rougher terrain much more enjoyable. Changing gears is super easy with the 21-speed twist shifters. Whether you're going uphill and need a lower gear, or flying downhill and want to pick up speed, a simple twist of the wrist gets you where you need to be. It shifts smoothly, so you're never struggling to find the right gear. I also really appreciate how lightweight yet sturdy it feels. It's easy to maneuver, which is great for weaving through paths or even just getting it on and off a bike rack. And when you need to stop, the brakes are reliable and give you plenty of stopping power. Overall, the Mongoose Flatrock is a fantastic bike for anyone who wants to enjoy the outdoors. It's built tough, rides smoothly, and is just a lot of fun. Whether you're a casual rider or looking to explore a bit more, this bike is a great companion! ... show more
Reviewed in the United States on May 22, 2025 by Burning Man
    • Worth it
Color: Red Size: 18-Inch Frame/29-Inch Wheels
Great fit for my 6 foot tall teen son. It's a nice sturdy bike that should last him quite a while. The seat gets a little uncomfortable when he takes long bike rides so we will change that out but that's the only complaint he's had.
Reviewed in the United States on July 8, 2025 by Michelle Hodgson
    • "You Get What You Pay For" Should be the Title for Every Bike Purchased in this Price Range
It's a really heavy Mongoose but .. I knew that when I pressed the "add to cart" button. The hardware on the bike is mediocre but .. knew that. The bike does everything you need it to do .. unless you're a "bike person". If you ride this too hard .. it breaks. If you use it for transportation, or if you need a good beater for your kid who will be throwing this at the ground repeatedly until they move out of your house chasing some dream job in cosmetology or whatever nightmare they're dreaming of .. this is the bike for you. Assembly was complicated by the fact that it's just an okay bike. The tools they include are enough to assemble the bike with but, you can cut your assembly time in half if you just have some basic tools lying around the house. The bike rides and feels fine. With some fine tuning on the brakes and shifter mechanism, the bike would stop and shift fine. Solid "bang for the buck" on this but, if you spend another couple hundred bucks, there are better choices that would be worth much more than the extra investment. All in all .. this is okay and it's fine unless you're really trying to do anything outside the realm of "commuting". ... show more
Reviewed in the United States on July 27, 2023 by Sean C.
    • Nice bike for the price.
Great bike and worth the money. Mongoose is a good brand.
Reviewed in the United States on August 2, 2025 by Amazon Customer
    • major component failure in less than 35 miles of riding this bicycle
Color: Red Size: 18-Inch Frame/29-Inch Wheels
hi,,when i first received this bicycle it looked well made,,the frame looked good,the wheels looked good...etc..mongoose bicycles have been around for a while...didn't think there should be any problems...i rode the bicycle for approx,,,one week,,each time i rode the bicycle 6 to 8 miles [on a paved road] i had rode a total of 35 miles i was finishing a ride about a half of a mile before i reached home...i was going about 5mph then suddenly i hear this loud noise i jump off the bicycle to see whats going on,,i see that the rear derailleur sheered in half ,,moving forward on the drive chain into the rear wheel,,the other half of the rear derailleur was hanging there broken in half..i couldn't believe this happened....,only 35 miles in total luckily i was close to home about a 15 minute walk...i've been riding bicycles for over 60 years and have never seen a derailleur failure like this..this is a shimano labeled derailleur ..this derailleur should be recalled immediately luckily i didn't fall off the bicycle with a injury...the center piece [a casted item] of that shimano derailleur completely failed obviously poor quality control/low ball manufacturing/metallurgy,,,i lost complete confidence in this bicycle,,,what a disappointment,,i called amazon customer service,they helped,,its been returned i am still waiting for my refund..thats my story,, ... show more
Reviewed in the United States on February 26, 2024 by travelman
    • Doesn't live up to the old Mongoose reputation
Its alright. I had Mongoose a long time ago and thought this would last longer for my son than the Huffy that started breaking in a year. Unfortunately we've replaced plenty of parts on this already also. Just not made as well anymore.
Reviewed in the United States on April 23, 2025 by Amazon Customer
    • Good quality
Color: Grey Size: 17-Inch Frame/26-Inch Wheels
Excellent mountain bike for the price
Reviewed in the United States on July 24, 2025 by Kimberly
    • Easy to Assemble and Meets My Needs
I live in a medium-sized neighborhood; I bought this bike to more easily travel within my neighborhood without having to use my car for very short trips. I have never assembled a bike before, but I was able to assemble this one quite easily. The instructions were a bit confusing, because instructions are included for several different versions of the bike, but once I acclimated to which instructions were applicable to me, it wasn't very hard. I did have to purchase a few items for assembly, but they were not very costly, and they will be useful additions to my toolbox. Assembly really only entailed attaching the handlebars, seat and pedals. All of the gear mechanism was already assembled. The bike is easy to ride and operate. So far, I'm completely satisfied with this purchase! ... show more
Reviewed in the United States on October 20, 2022 by Wendi McDaniel

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