So I was cleaning up my bike today and I noticed that the part I always assumed was the dust cover was loose on my bike. That seemed bad so in order to get a better view of the problem, I pulled the crank and took a look.
My question is: What is the notched part I'm holding to the left of the crank (I always persumed it to be part of a dust cover)? Why does it appear to me that this is somehow sheered off? What do you do about that?
I'm never dealt with a bottom bracket before but I can do almost anything else...