I have motorized several bikes in the past. Cheap Chinese kits are just that,,,, cheap. Better quality motors from Subaru, Honda, etc., are much better. I like a friction drive for it's simplicity & ease of any repairs . You can easily raise it off the tire & pedal. Changing a flat tire is much easier , too with one. I prefer an older middleweight or balloon tire , 1950's - 1960's frame , rather than your Schwinn . The shaking , vibrating , harsh ride with the motor on your Schwinn will beat the bike & you. Check local laws before spending your money . This site will help you.

http://www.motoredbikes.com/