Re: Beach cruiser concearns.
A motor, any motor is only "crud proof" if it has a good air cleaner and protection from the environment it is operating in. Chain saws are designed to run in areas of high concentration of gritty stuff. They use a good air cleaner element and the operator must be aware of regular cleaning and maintenance. Ask the Army dudes what is their biggest concern with weapons and vehicles they have while operating in the desert. They'll tell you, "sand" . Same goes for jet engines and helicopter transmissions. Grit will kill any mechanical thing if allowed to get into the works. Keep that in mind when you hit the beach no matter what motor you choose to install.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"