• If I've understood you correctly, you have a choice:

    • a new headset with a greater stack height;
    • get your LBS to cut the thread further down the steerer.

    Of the two, the second would be my choice. Finding another HS with just the right dimensions to fit within such a narrow margin will be a PITA and end up costing you two HS; getting the thread cut will be cheaper than a new HS and give you more leeway too adjust it correctly: 14mm is very short, probably forks from a much larger frame that have been cut down.

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