I suffered bike death last night on the way home. Thankfully the mechanical failure (which I heard) occurred about 1/2 a mile away from the house so I didn't have too far to push the bike. I'm not sure what failed but the rear wheel had a slightly eccentric rotation in the morning. After something audibly snapped the wheel rotation went completely weird and it basically stuck to the side of the frame. This necessitated me pushing the bike home with the wheel dragging along the floor giving me pause to think how useful a mechanical contraption the wheel is when it's working.