These all let go at once. It was badly worn and I had the replacements and chain but hadn't managed to make time to change them.
I was on the way to work and there is a silly little round-a-bout in a backstreet that I usually just ride over the top of but when I gave it a handful to get the front wheel up it just chewed the teeth off the sprocket. I'm amazed that there are actually two left!!
The bike is a Husqvarna TE450.
