 Downhill frames are also overbuilt to handle the stress of riding over rocky terrain, drops, and jumps.Bike weights have been typically over , but modern downhill bikes have broken the weight barrier (with some custom builds on carbon frames weighing between 27-29 pounds) Some newer (2014/5) downhill bikes can be built to weigh under , such as the Trek Session 9.9 or Kona Supreme Operator.Adjustable head tube angles are also available to adapt the bike to the owner's preferred style of riding.