woom OFF AIR 4
Bike: 20″ wheels  •  19.9 lbs
Child: 6 - 8 years  •  46″ – 51″ height

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Accessorize Your woom

CYCLOPE Bike Lights
LOKKI Bike Lock
KIDS' Helmet
NEEBOWS Elbow Pad Set
NEEBOWS Knee Pad Set

woom OFF AIR 4

Get out and explore

The woom OFFAIR 4 gives children aged six years and older a superlight and durable mountain bike for their first go on the pump track and easy cruising through forests and fields. The kink in the top tube makes it easy to get on and off quickly in any situation, thereby giving kids greater safety out and about on the trails. The perfect introduction to mountain biking.

Size: 20″ wheels
Weight: 19.9 lbs (without pedals)
Age: 6 - 8 years
Height: 46″ – 51″ height
Available editions:
Get out and explore
  • Lightweight Aluminum Frame

    The superlight aluminum frame with butted hydroformed tubes has a sporty geometry, long wheelbase and flat steering angle. The kink in the top tube makes it easy to dismount quickly in any situation.

  • Suspension Fork

    Comfort and control on the bumpiest terrain is a given thanks to the high-quality suspension fork, which can be adjusted to the rider’s weight. Tune the feel of the bike to suit the terrain with adjustable compression and rebound damping, plus lock-out the suspension when needed. These features ensure a good time, whether your child is shredding up the trails or cruising home.

  • Innovative Braking System

    With their excellent modulation combined with special brake levers designed for children's hands, the disc brakes increase safety and control in all situations, including on rough terrain and in wet conditions.

  • woom Stem

    Made from forged aluminum, the specially developed stem guarantees maximum stiffness with minimal weight. Thanks to its flip-flop design it can be turned over and mounted upside down to adjust the handlebar height.

  • Ergonomic Contact Points

    The saddle is one of the most important points of any kids bike. It significantly impacts the ability to ride longer distances and rougher terrain. That is why we have designed our saddle to fit the anatomy of children and give them a slightly stretched riding position. Perfect for a comfortable riding experience!

  • Gears

    The precise and easy-to-operate gear system allows smooth shifting. The SRAM X5 system has nine gears suitable for a wide range of gradients thanks to 28 teeth in the front and an 11-32 cassette in the back.

  • High-Quality Tires

    The high-quality Schwalbe mountain bike tires with ADDIX SPEED rubber compound offer an ideal combination of low rolling resistance, maximum grip, good shock absorption and excellent durability.

  • Trigger Shifter

    The easy-to-use SRAM trigger shifter allows riders to shift smoothly and reliably through the nine gears using thumb and index finger.

  • Sticker set

    Personalize your bike! Every woom OFF is delivered complete with a set of stickers in four colors. Place them on your rims and top tube to personalize your bike!

“With the woom OFFAIR we are expanding our range to include a mountain bike that makes no compromises when it comes to design and quality.”
Marcus Ihlenfeld
Founder of woom

woom OFF AIR 4

Bike Geometry

Wheel size
Handlebar height
Steering angle
Top tube horizontal
Seat tube angle
Minimum saddle height
Maximum saddle height
Crank length
Handlebar adjustability
Angle +/-15°; Height +/- 0.47″

woom OFF AIR 4


  • Frame material: lightweight, high-quality 6061 T6 aluminum with butted and hydroformed tubes
  • 20″ wheels
  • Sporty handling: an easy-access low top tube, low centre of gravity and long wheelbase provide good balance and make for a fun, safe riding experience
  • 9 speeds
  • SRAM trigger shifter
  • SRAM X5 derailleur
  • Superlight woom OFF DISCO TEC double-chamber aluminum rims
  • Aluminum hubs with sealed industrial bearings
  • Thru axles for maximum torsional strength (100 x 15 mm front / 135 x 12 mm rear)
  • 20 G14 spokes, double-crossed spoking
  • Aluminum nipples
  • Hydraulic air suspension fork with 60 mm travel, adjustable compression and rebound damping, plus lock-out
  • Light carbon fork
  • 1 1/8″ – 1″ baby taper shaft
  • 100 x 15 mm thru axle
  • Post mount for disc brake
  • 20 x 2.25″ Schwalbe Rocket Ron with ADDIX SPEED rubber compound
  • Quality MTB tires with low rolling resistance, maximum grip, good shock absorption and excellent durability
  • Car-type valves for easy filling at any gas station
  • Fully integrated 1″ – 1 1/8″ headset
  • Sealed industrial bearings
  • Forged aluminum
  • CNC-machined
  • Handlebars attached via two clamps - +/-15° flip-flop design to adjust handlebar height
  • Length: 50 mm
  • Ergonomically designed to fit children's anatomy
  • Non-toxic
  • Side protection to lean against walls
  • Wide, ergonomically adapted and lightweight aluminum bars for more control
  • Sandblasted and silver anodised
  • Width: 580 mm
  • Rise: 20 mm
  • 27.2 x 250 mm
  • Anodised aluminum seatpost with insertion marks that indicate the minimum insertion depth
  • Child-friendly thanks to small diameter
  • 100% silicon for maximum grip
  • Non-toxic
  • Screwed-in end plugs
Seatpost Clamp
  • Made from aluminum
  • No risk of turning and/or twisting
  • Lightweight, forged 110 m aluminum 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
  • Cr-Mo axle and sealed industrial ball bearings
  • Hydraulic disc brakes from Promax
  • Disc diameter front/back: 140/140mm
  • Ergonomic brake levers designed for children's hands
  • Black
  • 17.2 lbs (without pedals)
Enclosed Tools
  • 4 mm hex key for stem and seatpost clamp
  • 8 mm hex key for front wheel and pedals
Shipping Details
  • 45 x 26 x 9 inches

Bike information
Max weight: 175 lbs (80 kg). Weights are based on time of information publication and are up-to-date. Weights may vary slightly, as we are always improving our bikes.
Time to assemble!

Any questions on assembly? We will be glad to help you out anytime!
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