Going on vacation with the kid, I had three bikes hung on the trunk mounted rack. After an hour or so, and silently noting a faint burning rubber smell, I then heard a loud "bang". I ignored that also. Stop for gas, checked the bikes, and found I had hung my faithful commuter with the front tire about six inches directly behind the exaust pipe. It melted my tire clean away. New tire and tube and tire strip and r strip already on (ouch) and planning a down turned exaust tip instalation today.