If that is the part that I'm thinking of (on mine), its just a plastic cap that snaps into place over the bearing race. If it's cracked, try contacting Fifteen G directly (the hive.com?) and get a replacement.
Interesting. I just picked up one of these cranks a couple weeks ago and I can't get mine to spin totally smooth and drag free. It feels like something is off. I'll have to check my caps when I get home. Maybe one is dragging. I only have one spacer and at 30 ft. lbs. It spins smoothly, but it feels too tight.
My caps did that when I installed my bb a few months back. My crank also didn't spin super smooth. The fix? Reface the bb shell. Seems this crank is very picky when it comes to shell widths.
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