Re: Is it possible to Motorize a bike with coaster brake?
Coaster brakes on vintage bikes seem pretty good in my opinion. I don't know about the new ones. A brake up front is essential even if you ride at very moderate speeds. If the chain derails or breaks, there's nothing to stop you. A caliper brake up front is OK, drum it better, disc (I'm told) is best. I'd keep the coaster brake and add the caliper brakes you have ordered. Unless you're screaming around trying to set land speed records it should be plenty good. The faster you go then the faster you need to be able to stop.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...