Whilst the internal diameter of the headtube is 1 1/8 inch, you'll only be able to fit a 1 inch steerer tube in there. You want 1 inch forks, not 1 1/8 inch.
@Bearlegged started
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Whilst the internal diameter of the headtube is 1 1/8 inch, you'll only be able to fit a 1 inch steerer tube in there. You want 1 inch forks, not 1 1/8 inch.