In Florida, Gene Vance was a schoolteacher, principal and hotelier. But when he moved to Oregon, he decided he'd try something different: selling bikes in his front yard. Cyclists on the busy Southeast Salmon Street bike corridor can see the inventory of Mean Gene's bike shop on the parking strip outside his house on the corner of 15th Avenue.

"Two or three times a year, I do get mean," says Vance, 80. "It's when people insult my bikes or try to tell me what to do when they bring bikes in for me to work on."

Vance stopped riding after breaking his back in a fall last year, but that didn't dull his enthusiasm for shopping at garage sales and thrift shops for investment material.

"I look for something that has possibilities, not Walmart bikes," he says. "I want something I can improve." He tries to buy a bike for under $40, apply elbow grease and—if needed—new parts. The goal is to double his money.

In a good week, Vance might sell a bike a day, but he says his inner eastside neighborhood is changing as property values climb, and sales have been slow this summer.

Although his wife complains of being the equivalent of a golf widow, he'll keep fixing old bikes in his basement workshop until his own wheels fall off.

"I'll keep going until I kick it—course, I don't know how long that'll be," he says. "I just enjoy it so much."

But his shop's unusual location has also aroused suspicions. Vance says the police stopped by a couple of years ago to investigate an online allegation that he was selling stolen bikes. He satisfied their curiosity with a packet of receipts.

"I watch out for the can people," he says. "If they come along trying to sell a $200 bike for $25, I tell them I'm not buying."