Well, I've changed the chain on mine twice in the past year-and-a-half, but that's it. That's the only problem I've had and a lot of that, I think, had to do with riding on these sugar sand (fine grain sand) roads. One of which I have to ride if I'm going anywhere, because it's the road to my house.
Right after I got mine, my Dad, who is now 71, liked it so much he went out and bought the same one with fenders and racks and he rides all over the town he lives in. I doubt if his bike sees any more maintenance than an shot of WD-40 on the chain once in a blue moon and I haven't heard of any malfunctions.