My husband thinks he would exercise to help with his diabetes if he had a bike. I think it's a ploy to get anoter toy, but I am willing to try it. He's a big guy, about 275 pounds, so does anyone know anything about bikes in here and what might be an appropriate size for someone like him? He also says he won't wear a helmet because his head is too big. I told him no helmet, no bike, so does anyone know of any good, but cheap, helmets out there he would be comfortable in?