Going to lube my chain last night and I noticed the crank was really hard to spin. Long story short, found that the BB shell is about 89.5mm but the BB cups, pressed into the plastic tube thing, are about 90.5mm (numbers made up) apart. Upon reinstalling cups into shell, I found that I could slide the whole assembly back and forth. It's been like this since I got it but I've never had a BB30 before so I didn't know that little gap was abnormal. What am I doing wrong here?