Extralite Ultrastar (2)
Moderator: robbosmans
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it's a bit easier to put into the fork when the steerer's inner diameter is on the small side(i think it has 1 or 2 threads more). also iirc it's tightened with an 8 mm allen key and not with a 10 mm(this could be wrong and i'm just too tired to go and check;-))
Simon is right, it's an 8mm.