woom ORIGINAL 4 Kids Bike - 20-Inch Wheels and 7 Speeds
Published on 09/24/2026 at 08:41 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS
woom ORIGINAL 4 is a 20-inch children's bike for riders ages 6 to 8. Its low aluminum frame, narrow tires, and twist shifter give the model a compact setup for paved roads, neighborhood paths, and light dirt riding.
Light Frame, Child-Sized Fit
The bike uses an AA 6061 aluminum frame and weighs 16 lbs. 14.4 oz. without pedals, according to REI's specification listing. Its 20-inch wheel size suits children from 45 to 50 inches tall.
The adjustable Vario stem changes handlebar height and reach, while the quick-release seatpost clamp allows tool-free saddle adjustment. The bike also includes a low standover design, ergonomic grips, reflective pedals, and a preinstalled kickstand.
Seven Gears and Rim Brakes
woom ORIGINAL 4 uses 7-speed gearing with a microSHIFT MS29 twist shifter and a microSHIFT M21SS rear derailleur. The drivetrain has a 28-tooth chainring and an 11-28-tooth rear cassette, giving the bike a broader range than a single-speed children's bicycle.
Front and rear V-brakes use reach-adjustable levers designed for smaller hands. The Schwalbe Little Joe folding tires measure 20 x 1.4 inches, and the aluminum wheels use 20 stainless-steel spokes. There is no suspension, so the bike is aimed at pavement and modest unpaved paths rather than rough mountain-bike trails.
Price and Current Position
REI lists the woom ORIGINAL 4 at $599.00. That price places it above basic 20-inch children's bikes, while the specification centers on low weight, child-specific geometry, adjustable contact points, and a geared drivetrain.
The current woom range also includes the woom GO 4, which has 20-inch wheels, 7 gears, a listed weight of 17.2 lb, and a $659.00 price on woom's US site. Compared with the ORIGINAL 4, the GO 4 is 0.2 lb heavier and uses a newer child-oriented shifting setup.
Who It Fits Best
woom ORIGINAL 4 fits children ages 6 to 8 who are ready to move from a single-speed bike to gears. Its 20-inch wheels, 7-speed drivetrain, 16 lbs. 14.4 oz. weight, and adjustable stem suit growing riders who need a light bike for neighborhood riding and mixed paved surfaces.
The principal limitation is the rim-brake and rigid-fork layout. Riders seeking hydraulic disc brakes, front suspension, or equipment for rocky trails need a different category of bike, while families prioritizing low weight and simple child-sized controls get a focused all-rounder.
woom ORIGINAL 4 at woom
The US product page details the 20-inch bike's geared drivetrain and child-specific fit.
woom ORIGINAL 4 Specifications
- Product: woom ORIGINAL 4 20-inch kids bike
- Manufacturer: woom GmbH
- Category: Geared children's bicycle
- Wheel size: 20 inches
- Weight: 16 lbs. 14.4 oz. without pedals
- Gearing: 7 speeds
- Tire size: 20 x 1.4 inches
- Price: $599.00 (as of 09/24/2026)
- Target audience: Children ages 6 to 8, 45 to 50 inches tall
