The Trek FX 2 (Gen 4) is a hybrid bike — representative silhouette: Hybrid. We have read 9 specification sheets (Trek Bicycle Corporation, Formula, Tektro and Trek) and recorded 20 fit facts from them. 12 of the 16 measurements a hybrid bike needs to answer fit questions are on file; 4 are confirmed by two independent sources. Where a measurement is missing, we say so below — we do not guess.
| Rear axle spacing | QR, 135 mm |
|---|---|
| Seatpost diameter | 27.2 mm |
| Maximum tyre width (frame) | 40 mm |
| Wheel size (ISO bead seat) | 700c / 29" (ISO 622) |
| Front axle spacing | QR, 100 mm |
| Brake mount, front | Flat mount |
| Rotor interface (hubs) | 6-bolt (ISO) |
| Maximum rotor, front | 160 mm |
| Maximum rotor, rear | 160 mm |
| Brake actuation | Hydraulic disc |
| Brake pad shape (fitted calipers) | Tektro / TRP 2-piston hydraulic & TRP mechanical (E10.11 pad) |
| Freehub body | Shimano HG, 8/9/10-speed body (also 11/12-speed MTB HG cassettes) |
| Rear speeds | 9 speeds |
| Chain standard | Shimano LINKGLIDE / CUES 9–11-speed |
| Stem bar-clamp diameter (fitted stem) | 31.8 mm |
| Handlebar clamp diameter (fitted bar) | 31.8 mm |
| Rotor interface, rear hub | 6-bolt (ISO) |
| Brake actuation, rear | Hydraulic disc |
| Brake pad shape, rear caliper | Tektro / TRP 2-piston hydraulic & TRP mechanical (E10.11 pad) |
| Chain compatibility family | Shimano LINKGLIDE chain family |
Confidence: 6 facts are verified by two independent sources; the rest come from a single cited source ("derived").
Not on file (required for a hybrid bike): Bottom bracket shell · Derailleur hanger · Brake mount, rear · Pedal thread. The sheets we read do not state them; until a source does, confirm these measurements before choosing a part that depends on them.
- 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 4 of the 16 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.