A Trek 1120 touring uses a IS42 integrated upper headset (integrated, 42 mm). The dimensions, how to confirm it on your frame, and how it compares to the neighbouring standards.
Updated 05 September 2026.
What headset does a Trek 1120 touring use?
The headset fitment standard on a Trek 1120 touring, and how to pick the right part.
| Frame | Trek 1120 touring |
|---|---|
| Headset standard | IS42 (integrated, 42 mm) |
| Cup / bearing outside diameter | 41.8 to 42.0 mm bearing outside diameter |
| Steerer diameter | 28.6 mm (1 1/8 in) |
The Trek 1120 touring uses a IS42 integrated upper headset (integrated, 42 mm), a 27.2 mm class seatpost, a 12x100 mm front thru-axle at the front (12 mm x 100 mm, front) and a braze-on front derailleur.
Gravel builds are often 1x, so the front-derailleur mount can go unused. The 27.2 mm post is the class default; confirm the exact part before buying. The bottom bracket is covered on its own page.
SOURCES: Park Tool, Standardized Headset Identification System (SHIS) · BikeGremlin, Bicycle headset bearing standards (SHIS) · BikeRadar, Road bike axle standards: the complete guide
Questions and answers
What headset does a Trek 1120 touring use?
A Trek 1120 touring uses a IS42 integrated upper headset (integrated, 42 mm).