I am 71 and have a heart condition which somewhat limits my endurance, so this appealed to me in that I thought I could join some of my cycling friends on 30k plus rides they take on some pretty hilly terrain here in the interior of British Columbia. Well, it fills the bill perfectly. I still get a good workout supplying all the motive power most of the time and just getting some help from the [e-bike kit] motor when I encounter a steep hill. I haven’t even come close to running the battery down on several rides on the 30 k range.I got one of the smallest batteries rated for 12 miles (19 KM). I highly recommend it.