What’s different about the frame compared to the previous version?
Advanced tube shaping for high-end looks and ride quality.
Hidden cable and hose routing through the headtube.
Trek’s first road bike with UDH (Universal Derailleur Hanger).
Does the Domane AL Rim frame get any changes?
No - that is a carry-forward frame.
What is the geometry?
Endurance geometry, same as the Domane AL Gen 3.
Does the frame have internal storage?
No – internal storage is a Domane carbon-only feature.
How about fender and rack mounts?
Domane AL Gen 4 has hidden fender mounts, rack mounts, and a top-tube bag mount. Hidden fender mount hardware part numbers can be found in the Domane AL Gen 4 service manual.
What is the brake mount and max rotor size?
Flat mount, up to 160mm both front and rear.
What is the hub spacing?
100x12mm front, 142x12mm rear with a swanky new UDH-compatible countersunk thru-axle.
What type of bottom bracket?
BSA threaded 68mm
Is the bottom bracket compatible with 30mm spindle cranks?
No.
Max chainring size?
2x: 50/34
1x: 50T
Is that a round seatpost?
Yes – Domane AL Gen 4 uses a standard 27.2mm round seatpost.
Is it compatible with the Madone SLR bar/stem?
No – the Madone SLR bar/stem’s profile will not interface correctly with the standard round headset cover used on Domane AL.
OK, fine. What about the RCS Pro stem?
Yes! You’ll just need a compatible headset cover (W5274267) and spacers (41357).
Are those new handlebars?
Good eye! Yes, Domane AL Gen 4 comes with all-new Bontrager Comp alloy handlebars that feature a shorter reach measurement (80mm), slightly shallower drop (121mm), and a 4mm total flare at the drops (2mm per side). Look at the Spec section on each bike’s Trekbikes.com page to see which bar is spec’d with which size bike.
Are the wheels tubeless compatible? What additional parts are required?
The wheels are tubeless compatible, but the tires and rim strips are not. To convert to tubeless, you’ll need to purchase tubeless ready tires, rim strips, valves, and sealant.