Recumbents are an HPV not a bicycle according to the UCI. Has alot to do with the bottom bracket distance, seat and frame geometry and such,and I do know they cannot hold any bicycling records, again according to UCI rules. However I do believe that a recumbent does hold the world speed record for a two wheel Vehicle. Check out The History of the Recumbent Bicycle: Winning Forbidden.the storys there: April 1, 1934. Recumbents Banned from all UCI Sanctioned Racing: do a goggle search for cycling records and you will find your answer. The bottom bracket had to be between 24 and 30 centimetres above the ground.
The front of the saddle could only be 12 centimetres behind the bottom bracket.
The distance from the bottom bracket to the axle of the front wheel had to be between 58 and 75 centimetres.
