Funny, I was doing a trail this weekend and on this one hard jump I started peddling and it felt like I had a flat. I stopped and checked my tires and they seemed A-OK. Peddled again and yet again it just felt sluggish like I had a flat tire. Finally after a look over I noticed that the charger plug popped out. Plugged it in and back in business. You don't realize how much you get use to the electric assist until it goes out. ha ha