LOWER EAST SIDE — Size matters at this skateboard shop.  The growing trend of longboarding — skateboarding on a longer, wider board that’s more reminiscent of surfing — has forced one Lower East Side skate shop to expand to meet the demand of its increasing clientel.  “The growth of longboarding has been explosive,” said Rob Perry, 34, manager of the Longboard Loft at 132 Allen St., an offshoot of Brooklyn-based Bustin Boards, which nearly doubled its retail space to accommodate the increase.  What was once a “fringe activity” is now a sport that is captivating everyone from lawyers and plumbers to the average skateboarder, Perry explained.

In response, the store between Rivington and Delancey streets, has expanded to 1,200 square feet, hired more personnel and added features like a “riders lounge,” he said.  Patrons can get custom designs on their longboards at the Longboard Loft on Allen Street.  “We’ve more than doubled our staff and our floorspace,” Perry said. “It’s intense, but a lot of fun at the same time.”  The newly designed store, completed at the beginning of June, includes more products like boards and protective gear, as well as one-of-a-kind hand-printed decks. The Longboard Loft also created a “riders lounge” where boarders can watch the latest longboarding videos.

“With the growth of the longboard scene, we realized that nobody was really servicing the broad needs of the community, and customers were being forced to order specialty items online,” Perry said.  Longboarding has its roots in the traditional skateboarding scene, but utilizes a larger board with thicker and softer wheels. This allows riders to cruise and carve along streets, making it a more viable form of urban transportation than shorter, trick boards.

“It can turn a boring half-hour walk across Manhattan into a seven-minute adventure, or a trip across the Williamsburg Bridge into a snowboard-like downhill run,” said Perry, who only picked up the sport himself a few years ago.  For downhill longboarders, who wear helmets and leather racing suits, they can reach speeds of up to 60 mph.   The Longboard Loft first opened in 250 square feet of space near Bustin Boards’ warehouse in Williamsburg to give riders a retail option.

Then, in April 2011, the shop moved into 750 square feet at the Allen Street address before expanding again this month.  DeNell Todd, 50, a retail assistant at the store, said customers from all backgrounds come in to obsess over their longboards.  “We have guys who are electricians, guys who are pilots, plumbers,” he said. “Some guys pull up with a Bentley.”

The products at the store are also diverse. Customers can walk out with a street-ready ride for $170 to $2,000. A pair of expensive trucks, which connect the wheels to the board, can sell for $500.  Todd, who has been riding for five years and also got his kids involved in the sport, can be found most mornings in Central Park.  For Todd, longboarding in the city requires “hyper-awareness” — with texting pedestrians and skittish cabdrivers clearing his mind of any other distractions.   “You are not going to be thinking about anything,” he said, “except where you are.”