This bike is made for kids who want to monster-truck over everything in their path. The kids' Diamondback El Oso Nino fat bike fits riders 44–54 in. tall, aged approximately 4–9 years old.
- This little bear's frame and fork are made from high-tensile steel for a smooth ride that's tough enough for prowling the neighborhood and the woods
- 4 in. wide tires offer amazing grip and sit atop 20 in. inch wheels, making for a unique style and ride
- Low tire pressure allows the bike to grab every bit of traction available, with extra float for soft surfaces and sand
- Apex mechanical disc brakes with 160 mm rotors front and rear provide great stopping power, allowing riders to go wherever the trail or their imagination takes them
- Shimano Tourney 1 x 7 speed drivetrain with Revo Grip Shift has 7 speeds to keep shifting simple and easy to master; Shimano grip shifter lets them charge up hills
- NOTE: Specs and images are subject to change based on component availability
Imported.
- 1 year of free adjustments (see more below)
- In-store bike assembly
- Pickup in store or curbside
- Bike experts available at 170+ bike shops
- 20% off shop services
- Free tubes with purchase of flat tire repair (Co-op Cycles brand tubes only; tube must be installed at time of purchase)
New bikes go through a normal break-in period, after which they should be readjusted. All bicycles sold at REI include free adjustments for one year after purchase date—as many times as you need. Included: derailleur and brake adjustments, lateral wheel truing, hub and headset bearing adjustments, tire inflation and chain lubrication. Not included: replacement or installation of new components or accessories, any other services. Call your local REI Co-op Bike Shop for more information.
| Best Use | Mountain Biking |
|---|---|
| Frame | Hi-Ten steel |
| Mountain Bike Style | Fat-tire |
| Bike Suspension | No Suspension |
| Fork | Hi-Ten steel rigid |
| Crankset | 152 mm steel arms with 40T Single Ring |
| Bottom Bracket | Square Taper - 5pc |
| Shifters | Shimano Tourney RS35 Grip Shift, 7 Speed |
| Rear Derailleur | Shimano Tourney FT35, 7-speed |
| Rear Cogs | Shimano Tourney TZ21 7-speed Freewheel, 14-28T |
| Number of Gears | 7 gear(s) |
| Brake Type | Mechanical Disc Brake |
| Brakes | Apex mechanical disc, with 160 mm front and 160 mm rear rotor |
| Brake Levers | Alloy lever |
| Rims | Jr Fatty Alloy, 32 h |
| Front Hub | Steel 32 h disc, 3/8 in. nutted, 135 mm OLD |
| Rear Hub | Steel 32 h disc, freewheel, 3/8 in. nutted, 180 mm OLD |
| Wheel Size | 20 inches |
| Tires | Chaoyang 20 x 4.0 |
| Tire Width | 4.0 inches |
| Handlebar Shape | Riser Bar |
| Handlebar | Alloy, 560 mm wide, 22.2 mm bar bore |
| Stem | Promax 90 mm |
| Seat Post | Steel 27.2 mm |
| Saddle | Padded Jr. Diamondback |
| Pedals | 9/16 in. resin platform |
| Headset | Threadless |
| Chain | KMC 7 Speed |
| Weight | 30 pounds |
| Bike Weight | Bike weight is based on median size, as sold, or the average of two median sizes. |
| Gender | Kids' |
| 20 IN | |
|---|---|
| Height Range | 3'8'' - 4'7'' |
| Reach | 345 |
| Stack | 445 |
| Effective Top Tube | 508 |
| Seat Tube Center-Top | 254 |
| Standover Height | 576 |
| Head Tube Length | 115 |
| Head Tube Angle (degrees) | 71 |
| Seat Tube Angle (degrees) | 70 |
| Bottom Bracket Height | 240 |
| Wheelbase | 927 |
| Chainstay | 380 |
| Fork Offset | 45 |
Sizing Notes
Measurements are stated in millimeters unless otherwise indicated.
How we measure bikes
- Standover Height Standover Height is a measurement from the ground to the top of the top tube, measured at the midpoint of the top tube.
- Reach Reach is the horizontal distance from the center of the cranks to the center of the head tube, measured at head tube level.
- Stack Stack is the vertical distance from the center of the cranks to the center of the head tube, measured to the top of the head tube.
- Effective Top Tube Effective top tube is the distance from the center of the head tube to the center of the seat tube/seat post, measured parallel to the ground.
- Seat Tube Center to Top Seat Tube length is the measurement of the seat tube, from the center of the cranks to the top of the seat tube.
- Head Tube Length Head Tube Length is measured from the bottom to the top of the head tube.
- Head Tube Angle Head Tube Angle is the acute angle between the head tube and the ground (measured towards the rear of the bike)
- Seat Tube Angle Seat Tube Angle is the acute angle between the seat tube and the ground (measured towards the rear of the bike).
- Bottom Bracket Height Bottom Bracket Height is a measurement taken vertically from the ground up to the center of the cranks.
- Wheelbase Wheelbase is the measurement from the center of the front axle to the center of the rear axle.
- Chainstay Length Chainstay Length is the measurement from the center of the cranks to the center of the rear axle.
- Fork Offset Fork Offset, or rake, is the distance from the front axle to a line drawn parallel to the center of the head tube or steering axis.