NEW YORK, United States — There's no doubt Chuck Taylors are cool. But comfortable? Not so much.Converse plans on answering this long-standing critique today when it unveils a spiffier, pricier version of the nearly century-old sneakers. The biggest upgrade in the Chuck II, as the company is calling the revamped shoes, comes with technology imported for the first time from corporate parent Nike. Lunarlon, a lightweight, bouncy foam used in Nike's running and basketball shoes, will now be found in Chuck's rubber sole.Jim Calhoun, the 48-year-old chief executive of Converse, knows exactly what people say when they gripe about his shoes: "I love them, I just wish I could wear them for more than a couple hours." He knows from personal experience, too. During an interview last week at new headquarters in Boston's North End, Calhoun wore an untucked blue shirt, jeans, and black-and-white Chucks. Now he believes sneakers need to feel good to remain relevant. "Kids are growing up in a world where they know comfort, expect comfort, and won't stand for discomfort," Calhoun says.Creating a more supportive shoe doesn't sound like a groundbreaking project for a sneaker manufacturer, but few brands are quite as conservative as Converse. Simply messing with the Chuck Taylor All Star — as the iconic shoes are officially called — strikes fear into Converse fans and executives alike. The old-style Chucks are one of the best-selling shoes of all time, with more than one billion pairs sold, and still account for a majority of Converse's revenue. In short, people like the shoe as it has been and don't want to see it change. Calhoun says he gets letters imploring him not to screw it up or "put a swoosh on it." (That's not happening, by the way.)Chucks are that rare product that has remained a pop- culture mainstay for decades, worn by no less than JFK, the Ramones, Kurt Cobain, and Miley Cyrus. Inside the company, executives attribute much of that success to staying the same, staying classic, staying moderately uncomfortable. "We've never sold more Chuck Taylors, and the company has never been as big or profitable as it is today without changing the product,'' says Calhoun. "One of the curses of having an icon is a fear — particularly in the midst of success — of doing any changes."Converse is on quite a run. Sales rose 21 percent in the fiscal year that ended in May, surpassing Nike's overall growth rate of 14 percent, and hit $2 billion for the first time. Calhoun, who took the CEO job four years ago, decided that keeping up that pace meant embracing footwear innovation in earnest. Up to this point, newness at Converse has been centered on style and collaborations with designers like John Varvatos and Missoni, expected moves from a lifestyle brand.Adding Nike tech will make Chucks more comfortable and conform to a footwear trend that has even seeped into dress shoes. It also gives Converse a much-needed "benefits" story, Calhoun says, something shoppers have come to expect when deciding on a smartphone or a running shoe. Converse is also betting it will be able to charge more for an enhanced sneaker. The Chuck II, which also has better materials and a fully embroidered star logo, will fetch $15 more than the original. The price of high-tops will now be $75; revamped low-tops will sell for $70.Still, sneaker conservatism is a hard habit to break. When the Chuck II hits stores on July 28, the revamped shoes will be sold alongside the originals. "I believe when people know that they can get a Chuck Taylor that's super comfortable, they'll run to the Chuck II," Calhoun says. "Then we'll figure out what the opportunity is for the original Chuck."Calhoun took the helm at Converse a decade after the shoe maker filed for bankruptcy, following stints running major divisions at Levi Strauss and Walt Disney as well as a stretch at Nike in the late 1990s as a director of basketball apparel. Nike purchased Converse from a private equity firm for about $300 million in 2003, and by the time Calhoun showed up the retro shoes had already made a comeback and surpassed $1 billion in sales. But executives had little way to explain the sudden revival.Early on, Calhoun recalls, he asked his executives simple questions almost as an icebreaker like: "Who is our customer?" "How are we going to keep up this growth?" He got back such drastically different answers that he soon realized there wasn't a coherent plan. "It absolutely shocked me," Calhoun says.Nothing exemplified this more than Converse's insistence to keep holding onto its past by continuing to make shoes for playing basketball — even intensifying the effort — despite little recent success. The forerunner to the Chuck Taylor debuted in 1917 as innovative footwear for the emerging sport of basketball. By the 1940s, almost every NBA player wore them. Converse's dominance continued for decades, helped by endorsements from superstars like Julius Erving and Magic Johnson, even as Chucks evolved into a casual shoe. In the 1980s, however, Nike and Michael Jordan would combine forces to all but own the basketball market. Calhoun decided to exit hoops in 2012 as his team reconsidered the brand. "We stopped for a second and said let's figure out what's working and who we are," Calhoun says.The cross-generational, retro appeal of Converse can obscure the fact that the company pitches itself mostly at what Calhoun calls the "active creative kid," a teenager who doesn't identify primarily as a jock. That niche seems to be a good fit — sales have grown an average of 15 percent over the past three years. After the two-year project to revamp the Chucks, this appears to be just the beginning of a shift at Converse to create a company open to borrowing from Nike. The alternative, as Calhoun sees it, would be "a company that is trying to nurture the past."By Matthew Townsend; editor: Aaron Rutkoff.