The final word on bikes

If you are going to use the bike for anything but the most casual of uses, buy a bike from a reputable bike shop.

For off road on rough and steep terrain buy a mountain bike. For shorter rides on pavement, commuter travel, or smooth off-road trails, buy a hybrid. For racing, or long distance riding on up and down pavement, buy a road or racing bike. For back and forth to the local library, etc., buy a comfort bike or a cruiser. And always wear a helmet.