Click here for delivery/availability information in light of the current coronavirus situation.
Popup schließen
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
woom 4
Zoom Icon

Bike  20" • 16.09 lbs
Child  6 - 9 years • 45"-51"
$ 479.00
Color: ...
pre-order now - expected to ship in early May
Flat rate shipping to USA customers

The intro to gears!

The woom 4 is a dynamic bicycle that introduces children to gears!  Our SRAM X4 8-gear shifter expands the possibilities for the rider.  Whether they are out adventuring in an area with hills or going on a long commute in town, this 20" bike is as powerful as the growing child demands it to be.

  • Hassle-Free Assembly: All tools and easy-to-follow in-home assembly instructions are included.
  • The 20” woom 4 takes bike riding to the next level. Bike weight: 16.09 lbs; Designed for ages 6 to 9 years or overall height 45"-51”. 
  • Bike: This all-terrain bike introduces kids to gears. With 8 gears and light Schwalbe off-road tires, it is perfect for exploring and longer rides
  • Shifting gears: The SRAM X4 8-speed shifters boost the joy of riding and expand the rider's range. The gear ratio is designed to handle any terrain, from steep climbs to long descents
  • Accessories: Kickstand is included for free. Bell and other accessories can be purchased separately.
Size: 20"
Weight: 16.09 lbs
Age: 6 - 9 years
Height: 45" - 51"
Available variants:
Red / Blue / Green / Purple / Yellow

woom brake

woom bikes are equipped with two individual V-brakes. The levers are suited to fit small hands. Safely stopping requires little braking effort.

All components that are specifically designed with safety in mind have the kidsafe PLUS seal. Click the icons to find out more.

Riding a bike is more than just fun in exercising. Discovering the world means expanding one's horizon.

Christian Bezdeka
Founder of woom

Bike geometry

  • A Wheel / Tire size 20"
  • B Cockpit / Grip height 30.32"
  • C Steering angle 68°
  • D Horizontal toptube length 17.56"
  • E Wheelbase 32.48"
  • F Seattube angle 71.5°
  • G Minimum Seat Height 22.05"
  • H Maximum Seat Height 27.95"
  • I Crank length 4.33"
  • J Handlebar Adjustment individually adjustable


  • frame material: light, high quality Aluminum alloy 6061 with seamless tubes
  • 20" wheels and easy handling: low entry and very low sitting position, a long wheel base and forgiving steering geometry to provide good balance and thus more riding fun
  • light unicrown fork made out of aluminum
  • 1” shaft
  • self-aligning for easy stearing
  • fully-integrated 1" headset
  • sealed industrial bearings
  • integrated ahead clamp
  • forged aluminum
  • our new Vario stem makes the bike not only higher but also longer. The bike grows with the child.
  • handlebar fixed with 2 clamps and bolted with 2 x 5 mm Allen-key
  • wide, ergonomic and lightweigt with a slight rise for more control
  • sandblasted / black anodized
  • 580 mm width
  • reduced diameter suitable for tiny hands
  • non-toxic
  • screw in bar end plugs
  • light, forged 110 mm aluminum cranks with a narrow Q-factor (width between the pedals)
  • beginner gearing: 29 x 11-28T
  • plastic platform pedals
  • sealed cartridge
  • mini V-brakes
  • 2 brake levers with reach adjustability to fit small hands
  • high-quality Jagwire cables for reduced friction and smooth performance
  • 8-speed
  • SRAM grip shifters
  • SRAM X4 derailleur
  • ultralight Soopa-Doopa-Hoops aluminium rims
  • aluminum hubs with sealed bearings
  • quick-releases to install and remove wheels
  • 20 stainless spokes, 2 x laced
  • 20 x 1.4" Schwalbe Little Joe– woom edition folding tires
  • low-resistance tires with good damping, low rolling resistance and good grip
  • car-type valve for easy filling at each service station
  • reflective strips for better visibility
  • age-specific ergonomic design
  • non-toxic
  • additional added protection to lean on walls
Seat Post
anodized aluminum post withinsertion marks that indicate minimal and maximal insertion depths
Seat Post Clamp
  • aluminum / quick-release
  • long lever that is easy to use
  • does not twist when tightened
Enclosed Tools
  • 5 mm hex key for stem
  • 15 mm pedal spanner
16.09 lbs (without pedals)
woom red, sky blue, woom green, purple haze, sunny yellow
Shipping Dimensions
40.9" x 21.7" x 8.7"
Bike Information
Max weight: 154 lbs (70 kg). At woom bikes USA, we reserve the right to make changes to the information on our website at any time. Weights are based on time of information publication and are up-to-date. Weights may vary slightly, as we are always improving our bikes.

This is how we deliver your bike:
5 min., ready, go!


woom bikes grow with you

(optional purchase)

Kids grow quickly. Size and fit is important. Avoid making compromises and choose the right size bike for your child. This unique program is available to all of our customers and will allow you to size up to the next bigger bike as your child grows.

  • 40% back of the original purchase price.
  • We will reimburse 40% of the original bike purchase price when you order a new woom bike within 24 months.
  • Your old woom bike must be less than 2 years old and in rideable condition. Rideable condition means that you allow your child to ride the bike.
  • We manage the return shipping of your old bike. We will provide you with a prepaid return label.

Customer Reviews

Based on 32 reviews Write a review