Sean John — which retailers call the most fashion-forward brand in the industry — will launch the Sean John Collection over the holidays, selling silk button-downs, wool pants and heavy coats. Ecko Unlimited's Cut and Sew line will offer cashmere sweaters and premium Italian denim this fall, and FUBU's Fevolution plans more tailored and fitted silhouettes next spring.

Fashion experts say the changes reflect a maturing customer base. Young consumers who grew up with hip-hop are now professionals in their late 20s and early 30s who might want to dress up a bit more. Marc Ecko, designer and chief executive officer of Ecko Unlimited, said his Cut and Sew line caters to his own maturing personal interests as well as to a more professional clientele.

"I think the cycle we're in is a dress-up cycle," he said. "But it's not dressing up in the way that your dad dresses up."

Matt Grill, a 27-year-old resident of Evansville, Ind., said he preferred the classier fashions offered by brands like Phat Farm and Ecko over big-logo shirts that can make someone look like a "walking billboard."

"For myself, it's being comfortable and feeling good about what I got on. Personally, I don't want to look like anybody else walking around," Grill said.

Even hip-hop lyrics are validating the dressed-up look. Rap star Jay-Z's song "What More Can I Say?" released in November 2003, includes the words "And I don't wear jerseys, I'm 30-plus."

For companies like Ecko and Sean John to continue growing, they need to make an effort to appeal to a broader clientele without diluting their core image, said Arnold Aronson, managing director at Kurt Salmon Associates.

"This is not a walk in the park or somebody just experimenting in a very local market," Aronson said.

Five or six years ago, urban fashions were restricted largely to smaller inner-city shops. Now, urban labels comprise anywhere from 40 percent to 60 percent of the young men's department in Rich's/Lazarus/Goldsmith's-Macy's stores, said Gail Nutt, senior vice president of urban business development for the Atlanta-based division of Federated Department Stores Inc.

Urban brands now constitute $1.6 billion of the country's $50 billion menswear industry, said Marshall Cohen, a chief analyst with the NPD Group.

Yet retailers and analysts say some of the fashions may have lost some of their appeal with their original fans, urban youths, because the clothes have become too mainstream.

Companies can turn to lessons learned from brands like Tommy Hilfiger, which after a strong run in the 1990s became overly distributed.

Robert Shapiro, the owner of retailer S&D Underground, said many young urban designers have been influenced by European designers like Etro, Paul Smith, and Richard James. American designers like RyanKenny and Eizzo have integrated those styles into their own fashions, which include woven button down shirts that sell for anywhere from $190 to $550.

Although retailers cannot seem to keep the classier button-downs in stock, young men are certainly not abandoning casual jean shorts, jerseys or track suits. Rather, the fashion-conscious might mix premium denim with a $10 T-shirt, or wear a $250 button-down with a baseball cap, Quirk said.

Urban brand designers have shown that they want to be serious players in the men's fashion market. But the issue of becoming too commonplace will always pose a potential threat in an industry that relies on building its buzz from the streets, said Wendy Liebman, president of WSL Strategic Retail.