the light is supposed to blink the the bright light and steady in the dim light. but I have found it blinking in the basement of my shop. but you can make it go back to steady by turning on the high beam and back again.
56,000 miles and I still have not broken a chain on my mid drives, including our tandem. cheap parts, cheap wheels, crappy tires are far more of an issue for most. never even broke one on my recumbents years ago.