woom OFF AIR 4
The ultralight and durable 20″ mountain bike with front suspension, 9 gears and disc brakes designed for children aged 6 years and over.
Rare AIR
The newly upgraded 20" woom OFF AIR 4 will take its Rider beyond the beginning stages of their mountain biking journey. Stable, responsive, and equipped with a high-performance front suspension system, durable components, and tubeless-compatible rims and tires, it provides best-in-class value in its category. Off-road capable and kid-tested, this mountain bike was ergonomically designed for growing bodies and developing abilities. The woom OFF AIR 4 is more than capable on cross-country trails yet, uncompromising on gravel, pavement, or wherever the spirit leads your Rider.
Frame
- Frame material: lightweight, high-quality 6061-T6 aluminum with butted and hydroformed tubes
- 20″ wheels
- Easy-access low top tube to assist dismounting
- Long wheelbase and low center of gravity to aid balancing
- Featuring woom-specific molded chainstay protector
Gears
- 9 speeds
- SRAM X5 trigger shifter
- SRAM X5 rear derailleur
Suspension Fork
- RST SPEX hydraulic air suspension fork with 60 mm travel, adjustable compression, and rebound damping, plus lock-out
- 1 – 1 ⅛″ tapered steerer tube
- 100 x 15 mm thru axle
- Post mount for disc brake
Wheels
- Tubeless-compatible Alexrims wheelset
- Aluminum hubs with sealed industrial bearings
- Thru axles for maximum torsional strength (100 x 15 mm front and 135 x 12 mm rear)
- 20 G14 spokes, double-crossed spoking
- Aluminum nipples
Headset
- Fully integrated 1 – 1 ⅛" headset
- Sealed industrial bearings
Tires
- 20 x 2.25″ Schwalbe Rocket Ron with ADDIX SPEED rubber compound
- Quality mountain bike tires with low rolling resistance, maximum grip, good shock absorption, and excellent durability
- Presta valves, tubeless conversion ready
Stem
- Forged aluminum
- CNC-machined
- Handlebars attached via two clamps
- Rise/drop: +/-15° with flip-flop design to adjust the handlebar height
- Length: 50 mm
Saddle
- Ergonomically designed to fit a child’s anatomy
- Streamlined, mountain-bike-specific saddle design
- Side protection to lean against walls
Handlebars
- Wide, ergonomically adapted and lightweight aluminum bars for more control
- Tapered end to fit a child’s hand
- Sandblasted and silver anodized
- Width: 570 mm
- Rise: 20 mm
Seatpost
- 27.2 x 250 mm
- Anodized aluminum seatpost with insertion marks that indicate the minimum insertion depth
- Quick-release seatpost clamp
Grips
- Child-friendly because of a small diameter
- Single-clamp grip to prevent twisting
- Safety zone: extra rubber on the palm-facing portion of the grip for added comfort
- 100% silicone for maximum grip
Seatpost Clamp
- Quick-release seatpost clamp for easy adjustments
- Made from aluminum
Drivetrain
- Lightweight, forged aluminum, 4.3" (110 mm), kid-specific cranks with narrow tread (Q-factor)
- Narrow-wide chainring with 28 teeth in the front
- Cassette with 11-32 teeth in the back
- Flat pedals made from fiber-reinforced nylon
- Chromoly axle and sealed industrial ball bearings
Brakes
- Hydraulic disc brakes by Promax
- Rotor diameter front/back: 140/140 mm
- Ergonomic brake levers designed for a child’s hands
Weight
- Bike weight: 21 lbs 11 oz
- Max weight: 110 lbs combined weight of the Rider and cargo
Colors
- Black
- Terra Coppa
Enclosed Tools
- 4 mm hex key for the stem and seatpost clamp
- 8 mm hex key for the front wheel and pedals
Shipping Dimensions
45 x 26 x 9”
Model | Inseam | Height |
| woom OFF 4 | 22.8″ - 28.7″ | 46″ - 51″ |
| woom OFF 5 | 27.8″ - 33.7″ | 50″ - 57″ |
| woom OFF 6 | 30.3″ - 37.8″ | 55″ - 65″ |
| woom OFF AIR 4 | 22.8″ - 28.7″ | 46″ - 51″ |
| woom OFF AIR 5 | 28.3″ - 34.3″ | 50″ - 57″ |
| woom OFF AIR 6 | 30.7″ - 38.2″ | 55″ - 65″ |
Unsure how to measure inseam? Can't decide between two sizes? Check out our What Size is Right?article
Your OFF-road adventure can begin shortly!
In just a few steps, your woom OFF will be ready for its first ride. Check out this video to find out exactly what to do.
Assembly instructions
Instructions for Use
You can find more information in our service and help area.
The woom 10-year warranty
Inspiring children to love riding their bikes is our mission at woom. That's why we guarantee the premium quality of every bike down to the last detail with innovative technology and long-lasting materials.
We have full confidence in our bikes, which is why we offer a 10-year warranty on the aluminum frames, rigid forks, bars and stem once you've registered online.
30-Day Return Policy
If you buy a product directly from us that does not meet your expectations for any reason, you can return it within 30 days of the purchase — no questions asked. We will refund the full cost of the product and pay to have it shipped back to woom. Please note: We are unable to refund the original shipping cost from when you first purchased the product. The refund for the cost of the product and return shipping cost will be processed within 5-7 business days upon receiving the shipment.
Return Procedures
If you are returning a product, please initiate a return by clicking the link below. Please read through the following tips if you are returning multiple items or upcycling to ensure your return process goes as smoothly as possible. Thank you!
Keys to Success
- If you are returning a combination of any of the following items that cannot fit in the same box, please do this in 2 separate returns. Items include: Any model bike, helmet, rack, freewheel, or fenders. For example, if you are returning a woom bike and helmet/large accessory, one return would contain the bike, and the other return would contain the helmet/ large accessory.
- The same rule applies if you are returning multiple bikes. Please do a separate return for each bike.
- Please ensure you are choosing the correct reason for return in order to get the correct return label.
All domestic shipping costs after the initial shipment to you will be covered by us. We will send you a return shipping label and all you have to do is pack it up and bring it to the shipper.
For questions, please email [email protected]. You can also give us a call at 855-966-6872. We are here to help you.
If you spot a difference between the product page and what you received, it’s likely due to a change in our supply chain. Our Customer Experience team is always here to answer any questions that you may have.
