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Parts ranked by steerer diameter

38.1 mm (1 1/2 in)
EC49 headset standard has the highest steerer diameter in the dataset, at 38.1 mm (1 1/2 in).

Which part has the highest steerer diameter?

EC49 headset standard, at 38.1 mm (1 1/2 in), tops the 8 parts we hold a published steerer diameter for. The full ranking is below.

#PartsSteerer diameter
1EC49 headset standard38.1 mm (1 1/2 in)
2ZS55 headset standard38.1 mm (1 1/2 in)
3IS52 headset standard38.1 mm (1 1/2 in)
4EC34 headset standard28.6 mm (1 1/8 in)
5EC44 headset standard28.6 mm upper (1 1/8 in) or 38.1 mm lower (1 1/2 in) crown race
6ZS44 headset standard28.6 mm (1 1/8 in)
7IS41 headset standard28.6 mm (1 1/8 in)
8IS42 headset standard28.6 mm (1 1/8 in)

Data as of 2026-09-06.

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