Neon bicycle pants and T-shirts flickered out. Books about the environment are heading to the dump. And the movie "Bonfire of the Vanities" is going up in smoke.

In a Christmas season of weak consumer spending and widespread economic pain, these seem to be among the biggest commercial flops.

Marketers went into the holidays knowing that Americans were worried about the economy and reluctant to part with their dollars. So, many merchants took few chances -- by and large, they stocked their shelves with conservative fashions or products that appeared to be proven winners.

Stores also tried to keep their inventories lean to avoid getting stuck with piles of surprise losers. "We didn't have any big dogs," said Gail Dorn, a spokeswoman for Target Stores, a discount chain.

Still, there were Christmas duds aplenty. Take, for example, the parade of dolls designed to compete with Mattel's ever-popular Barbie.

Among them were Matchbox's Real Models, including likenesses of Christie Brinkley, Cheryl Tiegs and Beverly Johnson. They found that Barbie is one tough cookie.

"Anyone who goes against Barbie gets their head handed to them," said Larry Carlat, editor of the trade publication Toy & Hobby World. "Most little girls see these dolls as Barbie's friends, and girls would rather have Barbie than a friend."

Likewise, action figures aimed mainly at boys -- among them, "Beetlejuice" and "Police Academy" characters -- were thrashed by the Teenage Mutant Ninja Turtles, a repeat hit from last Christmas.

Not that all of last year's hot toys thrived again this year. Sales of Micro Machines -- inch-long replicas of cars -- sped downhill. In fact, many consumers turned away from the favorites of past years in the toy business and elsewhere.

Carlat said that the action figures based on the hit television show, "The Simpsons," were not "an out-and-out bomb or a stiff, but they didn't do nearly as well as expected." He said that the figures arrived in toy stores too late, in October, after "Simpson mania" subsided.

This year's books about the environment arrived too late and too numerous. "None of them sold," said an executive for Crown Books. "By the Christmas of 1990, people had had enough."

"They all are on recycled paper, but it's still going to mean throwing away a lot of paper," the executive added. "That's the ironic thing."

One of Crown's biggest disappointments: "Just a Dream," a children's story about ecology, written by Chris Van Allsburg, author of the previous best-seller "Polar Express."

Expensive gift and coffee table books also faltered, with the $30 price level being a breaking point. But there was at least one major exception to the rule: One of the season's biggest hits was "The Civil War: An Illustrated History," a companion to the public television miniseries. It sold at some chains for the full list price of $50.

Meanwhile, cookbooks staged a comeback. Biographies and autobiographies also did relatively well, including books about movie actress Ava Gardner, football and baseball star Bo Jackson and television newscaster Charles Kuralt.

But former President Reagan's memoir, "An American Life," was a disappointment even though it made the best-seller lists, including those in Washington. It trailed "Millie's Book," the dog's-eye view of the White House ghostwritten by First Lady Barbara Bush.

"It's been a joke in the industry," said Neal Webb, marketing director for Ingram Book Co., one of the nation's biggest book wholesalers.

In the fashion business, the neon fad faded, particularly on skin-tight bicycle pants. Why?

"The bulk of the 'baby boomers' are now past 40, and they can't afford liposuction," said Alan Millstein, publisher of Fashion Network Report.

Loose sweat suits fared much better, and men's neckties with bold or playful prints were an undisputed hit.

Other mass market fashion flops were corduroy, cowboy boots and, in particular, suede and leather coats. Millstein explained that because leather is so durable, many people who bought flight jackets and other leather apparel in past years don't need replacements yet.

In the sluggish consumer electronics business, electronic piano keyboards probably were the biggest disappointment, said Louis Block, vice president of merchandising for the Philadelphia-based Silo chain. After several years of selling briskly, keyboards are being hurt by competition from Nintendo and other video games, Bloch said.

One of the biggest hits, though, also was a consumer electronics product: the $60 Video Plus, an easy-to-use remote control device for programming VCRs.

Along with buying gifts, people normally flock to the movies during the holidays. This year, though, such highly promoted films as "Bonfire of the Vanities" and "Havana" have gotten off to weak starts. "Rocky V" also has been less than a knockout.

Their box office receipts may have been hurt by the glut of holiday season releases, with nine major films coming out since Dec. 19. In some cases, pans by critics may have hurt, too.

Citing two of the biggest Christmas hits, "Kindergarten Cop" and "Home Alone," analyst Jeffrey Logsdon of Seidler Amdec Securities suggested that "stories won out over stars." He said that moviegoers also seem interested in cheerful stories, perhaps as an escape from all of the economic gloom.

A notable exception was the explosive box office debut on Christmas Day of "The Godfather Part III," which Logsdon attributed partly to the loyal following developed by the first two Godfather movies.

Novelty items, as usual, had mixed results. Neiman Marcus stores, the tony retailer long known for its fancy, unconventional gifts, fared well with its $95 Silly Putty in an engraved sterling silver egg. The chain also succeeded with the 18-karat Golden Slinky, which went for $55.