Holiday bikes are bikes in a special event on a special month of the year. You can get them any time of the year, but Bike Race won't show what you have to do to get them until the month of the holiday comes or on Black Friday.
List of Holiday Bikes:
Liberty Bike
Santa's Bike
Halloween Bike
Easter Bike
Touchdown Bike
Thanksgiving Bike
Santa's Hog Bike
Love Bike
These are the Holiday Bikes: