Demographics say the average Harley owner is getting older and sales are down simply because us older riders can't ride anymore being all worn out from lifetimes of hard work. Who wants to retire and end up with busted knuckles and slipped discs from stoop labor on other peoples bikes? I think the best way to make money would be to buy and sell parts and used bikes. Any business you start will require capital, credit, insurance, licenses, accountants, permits, etc... sticking with E-bay and swap meets would be less physically demanding and probably more profitable for a retiree.