The Mantis Colossus is the new way to go. The 29-inch wheels help roll along any surface. Whether it is on the dirt or on the asphalt, the Colossus delivers with its front disc brake and Shimano rear derailleur. Find a new path to ride as you explore on the Colossus.Great news! If you select Site to Store delivery, you can call your local store as complimentary assembly may be offered at that location.