The Trek Domane AL 2 Gen 4 is a road bike — representative silhouette: Road endurance. We have read 5 specification sheets (Trek Bicycle, Shimano and Tektro) and recorded 31 fit facts from them. 12 of the 14 measurements a road bike needs to answer fit questions are on file; 6 are confirmed by two independent sources. Where a measurement is missing, we say so below — we do not guess.
| Bottom bracket shell | BSA / English threaded, 68 mm |
|---|---|
| Bottom bracket shell — 49 | BSA / English threaded, 68 mm |
| BB shell width | 68 mm |
| Derailleur hanger | SRAM UDH (Universal Derailleur Hanger) |
| Seat clamp diameter — 49 | 32 mm |
| Front derailleur mount | Band clamp, 31.8 mm |
| Rear axle spacing | Thru-axle, 142 × 12 mm |
| Seatpost diameter | 27.2 mm |
| Wheel size (ISO bead seat) | 700c / 29" (ISO 622) |
| Front axle spacing | Thru-axle, 100 × 12 mm |
| Brake mount, front | Flat mount |
| Brake mount, rear | Flat mount |
| Rotor interface (hubs) | 6-bolt (ISO) |
| Maximum rotor, front | 160 mm |
| Maximum rotor, rear | 160 mm |
| Brake actuation | Mechanical (cable) disc |
| Freehub body | Shimano HG, 11-speed road body (+1.85 mm) |
| Rear speeds | 8 speeds |
| Chainline | 43.5 mm |
| Rear derailleur max cog | 34 t |
| Rear derailleur total capacity | 43 t |
| Chain standard | 6 / 7 / 8-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 | Mechanical (cable) disc |
| Brake cable pull, front | Short cable pull |
| Brake cable pull, rear | Short cable pull |
| Front chainring count | 2 rings |
| Fitted outer chainring teeth | 50 t |
| Difference between front chainrings | 16 t |
Confidence: 17 facts are verified by two independent sources; the rest come from a single cited source ("derived").
Not on file (required for a road bike): Maximum tyre width (frame) · 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 2 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.