WOOM 4 | Bike 20 inch | 6-9 Years | 45"-51" | 17lb 8oz (7.9kg)



Includes Bell and Kickstand

Free Shipping, Free Returns Via UPS Ground 1-4 Days. 

For more shipping details click here. 

 Questions? Please call 855-WOOMUSA (855-966-6872) or email infousa@woombikes.com

Weight Age Size
17lb 8oz (7.9kg) (w/o pedals) 6-8 years 45-51" (115-130 cm)

The 20" WOOM 4 with its optimized geometry is build for enhance riding dynamics. With 8 gears and light off road tires it is perfect for exploring and an extended usage.



The WOOM4 bike has the following outstanding characteristics:

  • High quality and light components; Overall weight 17lb 8oz (7.9kg)
  • Geometry designed for the youngest of riders
  • 8- Speed SRAM X4 twister shifter (trigger shifter available at no charge)
  • Kickstand already installed


How is the bike delivered?

WOOM Bikes are perfectly prepared and almost completely assembled when they are shipped. Only a few small adjustments are necessary to get the bike ready to ride. Assembly instructions along with the necessary tools are included. 

  1. Install the front wheel. 
  2. Attach the head set and tighten the 6mm bolt firmly using the allen wrench. 
  3. Adjust brake 
  4. Install Pedals 
  5. Adjust saddle height and ready to go



For bike enthusiasts, here the details:
A Wheel / Tire size 20" F Wheelbase


825 mm

B Cockpit / Grip height


745 mm

G Crank length


110 mm

C Steering angle 68° H Seattube angle 71.5°
D Medium standing height


550 mm

I Minimum Seat Height


500 mm

E Horizontal toptube length


430 mm

J Maximum Seat Height 27.56"700 mm




Frame Material: Light and high quality A-6061 Aluminum - 20" wheel size providing agile yet good natured riding characteristics: low step in height, very low minimum seating position, long wheelbase, very forgiving geometry Set up provides maximum stability, and excellent balance resulting in increased satisfaction - Continuous seat post design allows for maximum saddle height adjustment


light unicrown fork made out of aluminum - 1" shaft - designed for ease of steering


semi-integrated 1" headset = sealed ahead set made out of steal and aluminum - integrated ahead clamp


Forged Aluminum - 40mm - +10° - no protruding screws in this fully integrated and proprietary clamp design - we call it the knee-friendly design - the handlebar is connected with two 6mm bolts
Handlebar wide, ergonomic, and light aluminum handlebar for more control - BMX style with high rise for maximum adjustability - sand blasted and black anodized - Width: 520mm
Handles reduced diameter for extra small hands - free of softeners and pollutants - grippy diamond structure - handle bar ends contain rubber plugs for additional cushioning and safety
Brake Two independent hand brakes (No Coaster Brake) - Mini V-Brake with levers suitable for small hands - brake lever with reach adjustability and ergonomic fit for very small hands - high quality Jagwire bowden cable for low friction and ease of operation
Crank Light forged aluminum cranks with 110mm length and low Q-Factor (low width between both legs) - Beginner ratio: 32T front and 11-32 rear - plastic pedals - molded cartridge chamber - Easy to operate V Hand brakes
Shifter 1x8 gears - SRAM X4 twister shifter for ease of shifting - SRAM derailleur with short cage
Wheels Super light Soopa-Doopa-Hoops Aluminum rims - small Aluminum hubs for extended leg room at the rear wheel - sealed bearing hubs - wheel can be installed and removed with 5mm allen wrench - 20 Niro spokes 1.8 straight spokes
Tires Kenda Small Block 1,5"x20 light weight low profile balloon tires offer great damping, rolling performance and a lot of grip - Schrader valves (car valves) to inflate easily
Saddle Age specific and ergonomically designed and molded - Free of pollutant and toxins - side safeguard to lean against wall
Seat post Anodized aluminum seat post - integrated maximum insertion indicator
Seat post clamp Aluminum quick release seat clamp with long lever for ease of use and operation - clamp is safely secured against unnecessary movements
Enclosed tools 1x6mm long allen wrench for headset, 15 wrench for pedals
Weight 17lb 8oz (7.9kg)
Colors Red, Blue, Green, Purple
Shipping dimensions 39.5" x 8" x 22"


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