The woom OFF AIR 4 is built around child-specific trail geometry for young riders progressing beyond everyday paths and onto proper off-road terrain. Its lightweight 6061 T6 aluminium frame uses a low top tube, low centre of gravity and long wheelbase to promote confidence and control.
An RST air-sprung fork with 60mm of travel adds front suspension for rougher trails, with rebound and compression adjustment plus lockout. Nine-speed SRAM X5 gearing and a 11-32T cassette give useful range for climbing and changing terrain.
Promax hydraulic disc brakes use child-specific levers for controlled braking, while wide aluminium bars, a flip-flop stem and an MTB-specific saddle support a purposeful trail position. The tubeless-ready wheelset and durable platform pedals are designed for active off-road use.
Features & Benefits:
- Trail-Specific Handling: Child-specific geometry and 20in wheels are designed to balance stability, manoeuvrability and confidence off road.
- Adjustable Air Suspension: The RST air fork offers 60mm travel with rebound, compression and lockout adjustment for rougher trails.
- Controlled Gearing and Braking: Nine-speed SRAM X5 gearing pairs with Promax hydraulic disc brakes for dependable climbing range and speed control.
Full Specification:
- Frame: Lightweight 6061 T6 aluminium with butted and hydroformed tubes; 20in wheels
- Fork: RST aluminium air-sprung suspension fork; 60mm travel; rebound and compression adjustment; lockout; 100 x 15mm thru-axle
- Number of Gears: 9
- Gear Shifters: SRAM X5 trigger shifter
- Chainset: Forged aluminium cranks; 110mm; narrow Q-factor
- Chainrings: 28T narrow-wide
- Rear Cassette: 11-32T
- Rear Derailleur: SRAM X5
- Pedals: Fibre-reinforced nylon platform pedals with metal pins
- Rims: Tubeless-ready Alexrims aluminium rims; 20 spokes
- Front Hub: Aluminium hub with sealed bearings; 100 x 15mm thru-axle
- Rear Hub: Aluminium hub with sealed bearings; 135 x 12mm thru-axle
- Front Tyre: 20 x 2.25in Schwalbe Rocket Ron
- Rear Tyre: 20 x 2.25in Schwalbe Rocket Ron
- Brakes: Promax hydraulic disc brakes; front/rear rotor diameter 160/140mm
- Handlebars: Wide lightweight aluminium bars; 570mm width; 20mm rise
- Grips or Bar Tape: Child-specific silicone lock-on grips
- Headset: Fully integrated 1 1/8in–1in headset with sealed bearings
- Stem: Forged CNC-machined aluminium flip-flop stem; 50mm; +/-15 degrees
- Saddle: Ergonomic MTB-specific saddle with side protection
- Seatpost: 27.2 x 250mm anodised aluminium
- Inside Leg or Age Range: 6–8 years
- Weight: 9.2kg without pedals
Manufacturers reserve the right to change specifications without notice based on availability at the point of assembly.
Information for woom kids' bike range:
Child-specific geometry – Lightweight frames, low riding positions and child-friendly geometry make woom bikes easy to handle, helping young riders feel stable and confident.
Child-specific cranks – Proportionally sized cranks and a narrow pedal position encourage a natural, comfortable and efficient pedalling motion.
Smaller grips – Slim ergonomic grips are designed specifically for smaller hands, providing comfortable and secure control.
Child-specific brakes – Easy-reach brake levers require little hand strength, making braking safer and easier for young riders.
Steering limiter [Selected smaller models] – Helps prevent the handlebars from turning too far, reducing the risk of over-steering while children develop their bike-handling skills.
Easy-to-use gears [Geared models] – Child-friendly shifting controls make changing gear simple and intuitive for developing riders.
Size Chart for woom Off Bikes
| Off 4 - Off Air 4 | Off 5 - Off Air 5 | Off 6 - Off Air 6 |
| Tyre/wheel size | 20" | 24" | 26" |
| Cockpit/handlebar height | 760mm (29.9") | 890mm (35") | 950mm (37.4") |
| Steering angle | 68º | 69º | 69º |
| Horizontal top tube length | 460mm (18.1″) | 525mm (20.7″) | 570mm (22.4″) |
| Wheelbase | 850mm (33.5″) | 970mm (38.2″) | 1060mm (41.7″) |
| Seat tube angle | 70º | 70º | 71º |
| Minimum saddle height | 575mm (20.6″) | 690mm (27.1″) | 765mm (29.1″) |
| Max. saddle height | 725mm (28.5″) | 845mm (33.3″) | 960mm (37.8″) |
| Crank arm length | 110mm (4.3″) | 130mm (5.1″) | 150mm (5.9″) |
| Handlebar adjustment | Angle +/-15° - Height+/-12° | Angle +/-15° - Height+/-12° | Angle +/-15° - Height+/-12° |
Warranty Information for woom:
woom offer a standard 2-year warranty that applies automatically from the day you buy a new woom bike. You need to provide the purchase receipt to make a claim under the warranty. Make sure you keep it somewhere safe.
Members of the woom Riders Club can extend the standard 2-year warranty on aluminum frames, rigid forks, handlebars, stems and cranks to 10 years for free. Log into the woom Riders Club here and register your woom bike within 9 weeks of buying it.
The 2-year and 10-year warranties can be transferred to you when you buy a used bike. The warranty period still applies from the date on which the bike was purchased as new.
Click here to find out more and to read the full warranty terms and conditions.