Easiest bike to add an engine to?

[Sidewinder Jerry]

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.bikesdirect.com/&ved=2ahUKEwiY7oivx9b6AhWVlWoFHY00DdIQFnoECAgQAQ&usg=AOvVaw2bCjmQFqZ3UhXbWDVB7k58

A favorite of Old Hippie of Yahoo Answers Cycling.

 

[CENTURION]

Were these kits designed around English 3 speed type bicycles? the smaller tubes and larger diamond seem perfect for them.

 

[redneckracing674]

it is sad. my huffy timberline went through 2 demo derbies, and got dropped 50 feet out of a tree onto some logs, and it suffered no damage, other than a bent wheel. i am comfortable to go 60+ on this same bike. I totaled a schwinn ranger, by jumping it, and breaking off the pedal, out of the aluminum arm. jb weld fixed it for a time.
i have a 1996 y26, by trek, withover 5000 miles on it, more jumps than are comprehendible, and i dont really take that good care of it, and i have never had a problem with it, besides a flat tire.
it is sad what bikes have become--throwaway toys