Most cheap bikes that are referred to as '24"' arr 24" wheel bikes... meaning a youth or kids bikes. If your friend is over 5'2" then a 24" wheel bike is too small... ie, a waste of $50. If it is an adult bike, then 24" refers to the frame size... a 24 " mountain bike is for someone 6'2 or up, and a 24" road bike is for someone between 5'11 and 6'2 or so.