 The wheelchairs used for each sport have evolved to suit the specific needs of that sport and often no longer resemble their everyday cousins.They are usually non-folding (in order to increase rigidity), with a pronounced negative camber for the wheels (which provides stability and is helpful for making sharp turns), and often are made of composite, lightweight materials.Even seating position may be radically different, with racing wheelchairs generally used in a kneeling position.