Used Off Road
Mountain bikes are specifically designed to ride rougher trails and unpaved surfaces. They will have flat bars, a low gear range to allow for climbs, and some combination of suspension. A “hard tail” mountain bike only has front suspension while a “full-suspension” mountain bike has both front and rear. Hard tail vs. full-suspension is very dependent on rider type, ride motivation, terrain, and comfort level. Hard tails are generally regarded as faster, so riders looking to race shorter distances will often go this route. Riders doing longer distances, rougher terrain, and/or riders looking for more comfort will often choose full suspension.
These bikes are one of the newer categories of road bikes. They are similar to cyclocross bikes in that they can handle many terrain types, including but not limited to, pavement, dirt, gravel, sand, grass, etc. The difference is that these bikes generally have larger tires than cyclocross bikes and sit the rider up higher for more use on longer distances and touring. These bikes are equipped with mount points for cargo and are a great all use bicycle.
This bike type will often look similar to a road bike in that it will have drop bars and a similar frame shape. This bike has a few unique features, however, that allow it to be used on a mixed surface course. The big difference is that this bike typically has wider tires and different tread that allows it to be used on a cyclocross course, typically consisting of a mix of pavement, dirt trails, gravel, sand, grass, etc.