I just got it today and i have the cups installed. i put the bearing in the bottom and the little silver metal seal thing over it. and i have the top and bottom cups installed (using the washer and screw method) but i have the bearings in the top cup but the part that u put on top of the bearings wont fit over my pro model stock fork... and i was told it didnt matter that this headset was threadless and my fork was threaded. why wont this piece fit...?