tca- 55-8-101:-(34) “Motorized bicycle” means a vehicle with two (2) or three (3) wheels, an automatic transmission, and a motor with a cylinder capacity not exceeding fifty cubic centimeters (50cc) which produces no more than two (2) brake horsepower and is capable of propelling the vehicle at a maximum design speed of no more than thirty miles per hour (30 mph) on level ground. The operator of a motorized bicycle must be in possession of a valid operator's or chauffeur's license, and shall be subject to all applicable and practical rules of the road. A motorized bicycle may not be operated on a highway of the interstate and defense highway system, any similar limited access multilane divided highway, or upon sidewalks; this is copied, form tennessee code. i could find no law stating anyone over the age of 16 is required to wear a helmet. check it out for yourself, but i have been riding without one for a while. here is the link to the entire tennessee code for anyone from tennessee that would like to double check, this info . http://www.michie.com/tennessee/lpex....htm&cp=tncode if you find a law stating adults have to wear a helmet, let me know. i don't need any tickets .