• Mounting a gas motor on a bicycle instantly creates a moped!moped image by fuxart from Fotolia.com
  
  Texas laws for operating a bicycle with a gas motor fall under three categories: moped operation laws, motorcycle operation laws and helmet laws. Texas bicycle law does not apply to any electric motor-assisted bicycles. When a gas motor is installed on a bicycle, it becomes a moped or motorcycle. However, several additional criteria must be met for a motor-driven bicycle to become a motorcycle.
  
  

Moped Operating Laws

• The Texas Department of Public Safety defines a moped as, "A motor-driven cycle whose speed attainable in one mile is not more than 30 miles per hour and that is equipped with a motor that produces not more than two-brake horsepower. If an internal combustion engine is used, the piston displacement may not exceed 50 cubic centimeters and the power drive system may not require the operator to shift gears." As gas motor bicycles are internal combustion engine cycles, they may not exceed 50 cubic cm engine sizes, the engine may not shift gears and the motor must generate less than 2 horsepower or the vehicle is considered a motorcycle. Mopeds must also travel under 30 mph. Driver's licenses are required for moped operation and are not issued to persons under the age of 15 in Texas.
  
  

Motorcycle Operating Laws

• The Texas Department of Public Safety defines a motorcycle as, "Every motor vehicle having a saddle for the use of the rider and designed to propel itself with not more than three (3) wheels in contact with the ground but excluding a tractor." Any bicycle with a gas motor that shifts gears, produces 3 or more horsepower, is larger than 50 cubic cm or travels faster than 30 mph are considered motorcycles. The State of Texas requires any person operating a motor vehicle--including motorcycles--to obtain a Texas driver's license.
  
  

Helmet Laws and State Approved Exemptions

• Persons under 21 in the state of Texas must wear a helmet while operating mopeds and motorcycles. Person over 21 are exempted from this law if covered under "an individual, group, blanket, or franchise insurance policy, insurance agreement, evidence of coverage, group hospital services contract, health maintenance organization membership, or employee benefit plan that provides benefits for health care services or for medical or surgical expenses incurred as a result of an accident," according to the Texas Department of Public Safety.