BOSTON - Each generation has a handful of toys that define it, landmarks that point to the different stages of childhood: Rock'em Sock'em Robots, hula hoops, secret decoder rings. For twentysomethings, the fondest memories of childhood often hark back to Big Wheels. Invented in 1969, the Big Wheel was manufactured by Marx Toy Corp. until 1985, when the rights to it were sold to Empire of Carolina (now Empire Industries). Jay Horowitz, president of Marx Toys, says the Big Wheel enjoyed its "golden age" in the early 1970s, before other companies duplicated the idea. "It's one of those few great classic items," he says.

But while the plastic roadster has become an icon of a generation now leaving youth behind it, Jay Doobrow, a product manager at Empire, says it has not faded from store shelves or neighborhood driveways. In fact, the Delta Tau Delta fraternity at Western Illinois University has held an annual big wheel race for charity since 1975. They say it often brings up to 1,500 spectators. Toys like Rollerblades, however, have lowered the average age of kids who like Big Wheels, Mr. Doobrow says. "But it's still a very recognized brand name. Mom and dad go to the store and say, 'I had a Big Wheel when I was a kid.' "