Worcester, Massachusetts, USA has many hills. I am, 78 year old male) and now am able climb them without too much effort with my upgraded bike. The major problem I had with the bike was the delivery uncertainty. Delivery was 5 months later than promised. I would not have minded it if I was informed on a timely basis of the delays. The problem was that customer service responded slowly and ambiguously. A minor problem was that the spokes on the wheel were not tightened. I had to tighten each one individually. When the package was delivered, it had everything that was promised packaged in an intelligent manner. EVERYTHING came in working order. Assembly was relatively easy except for installing the inline brake sensors. Overall I am a very satisfied customer; the upgraded bike is a lot of fun.