The woom GO 4 (2025) is a kids' bike — representative silhouette: Kids 20". We have read 1 specification sheet (woom) and recorded 13 fit facts from it. 7 of the 14 measurements a kids' bike needs to answer fit questions are on file; 0 are confirmed by two independent sources. Where a measurement is missing, we say so below — we do not guess.
| Front derailleur mount | No front derailleur mount (1x only) |
|---|---|
| Wheel size (ISO bead seat) | 20" / BMX (ISO 406) |
| Steerer tube | 1" threadless |
| Brake mount, front | Cantilever / V-brake posts |
| Brake mount, rear | Cantilever / V-brake posts |
| Rotor interface (hubs) | No rotor interface (rim brake) |
| Brake actuation | Cable rim brake |
| Brake pad shape (fitted calipers) | Rim pads: V-brake / linear-pull threaded stud (M70T4 / S70C, 70 mm) |
| Freehub body | Shimano HG, 8/9/10-speed body (also 11/12-speed MTB HG cassettes) |
| Rear speeds | 8 speeds |
| Shift actuation | Mechanical (cable) |
| Chain standard | 6 / 7 / 8-speed (7.1 mm) |
| Steerer clamp (stem) | 1" (25.4 mm) |
Confidence: every fact above comes from a single cited source — "derived" on our lattice; none is verified by a second independent publisher yet. A verdict that rests on a safety-critical fact therefore stops at "unknown" rather than "fits".
Not on file (required for a kids' bike): Bottom bracket shell · Derailleur hanger · Rear axle spacing · Seatpost diameter · Maximum tyre width (frame) · Front axle spacing · Pedal thread. The sheet we read does not state them; until a source does, every fit question that needs one of these reads "unknown" — or "unknown — safety-critical" where a guess could hurt you.
- Why do so many verdicts on this bike read "unknown"?
- Because a verdict needs the bike's measurement for every dimension a part requires, and 7 of the 14 required measurements are not on file. "Unknown" means we could not check — not that it fits, and not that it does not.
- Will the verdicts change?
- Yes. When a second independent source confirms a measurement — or a first one states a missing one — the verdicts are recomputed from the new facts. Nothing on this page is typed by hand.