https://streamable.com/e/z4181vI was riding a few miles daily a few months back and realised by arm cranks had some play in them, maybe a wobble of about 0.5cm. I noticed the hub cap on the left crank had become very loose, so I tightened it by hand with an allen key and just through tightening the hub cap the issue was fixed (in hindsight, this was a bad move).
Shortly after I would hear a very slight scraping sound that I thought was some kind of leaf of wrapper of some sort. As the scrape became more noticable over weeks I realised it was the inner chain ring scraping against some dirt. So I continued to ride.
It became more much and as I was cleaning from mud the problem became clear.
I was hoping someone could explain how me tightening the nut could have caused this to happen.
I know the inner chain ring is far too close to the frame to begin with, but I've been riding this bike for nearly 4 years without this issue.
What happened when I tightened the nut? Is it possible I have done permanent damage to the bottom bracket? I have never taken apart this section of the bike before so I'm a bit clueless.
I know you will be tempted to say the chain rings are bent because of the wobble in the rotation, but I have used an alignment tool to make sure they are straight individually.
Notice how both chain rings wobble and then you'll notice it's actually the whole piece, the rings, the crank arm, they all follow the same wobble. The misalignment is elsewhere.
If it is the bracket I would just like to know how this happened from me tightening the hub cap.
