about 2 years I was riding my bike and kept touching the chain to see if it was tight cause i tightend it earlier,and i was watching for cars then i peddled as i was touching it and ran 3 of my fingers through the sproket(chain smashed over my fingers)of the bike and looked at my hand in shock to see only 2 fingers there[].Its was nast looking..Luckily i got to the hospital in time to reattach them.