CAMBRIDGE — The space under the I-93 off-ramp that fans out from Exit 27 is loud. Really loud. Cars honk overhead; trucks at the Boston Sand & Gravel plant pour dusty loads from one pile to another; wind sometimes shakes the trees lining the Charles River.

But under the concrete stanchions supporting the Leonard P. Zakim Bunker Hill Memorial Bridge lies an oasis for skateboarders: The Lynch Family Skatepark.

Skaters find focus in the rumble, practicing their tricks for hours. Their jumps add percussion to the din, boards slapping and grinding against rails and pipes. The regulars, mostly men in their teens and 20s, come to practice, relax, and take the rare opportunity to compete against themselves instead of one another.

“This is Boston’s crown jewel of skateboarding,’’ said Ryan McGuinness, 19, a regular at the 40,000-square-foot park.

Since opening in late 2015, the space has become a hub for nearby skaters. It is one of only a few parks in the area, with those in Roxbury, Jamaica Plain, and Malden either far from public transit or not as well-maintained, McGuinness said.

After being chastised for skating on public art or public library steps or getting splinters from homemade plywood jumps, skaters have found solace in a place meant only for them. Here, they skate and smoke, a haven for the rebellious.

“I feel like my life is completely restricted, other than this,’’ said Tristan Webber, 22. “You do what you want when you want. That’s the glory of it.’’

Webber, who goes by TWeb$ around the park, drives here from his home in Worcester a few times a week to practice. When he was 7, a neighbor handed him a cigarette and a skateboard and told him to man up.

Webber dropped out of high school in ninth grade and has no plans to go to college, he said. But he grinds on the board, flicking his feet with an effortless habit earned through repetition. Webber spends hours practicing, learning the balance, feeling the way his toes can spin the board.

“If you don’t commit, you’re not going to land,’’ Webber said. “That’s the hardest part — getting yourself to commit yourself and do it.’’

There are few places where a teenager will practice a trick over and over purely for the pleasure of grace. One skater spent over an hour doing the same trick. Another comes almost every day on his lunch break. He glides and vaults. He flips and brakes. Each brings a unique style to the same moves, as there is no established right way to skate.

“Look at the way he’s pushing,’’ Webber said, nodding to a friend skating by, whose white T-shirt rippled as he jumped, rotating his board. “Look at the trick he did. Look at that. It’s freedom. You’re yourself.’’

Webber has dislocated his shoulder five times in the past two months, he said, and each time just popped it back in himself.

Such pain and injury seem frightening to nonskaters. But to the crowd at Lynch, the possibility of injury is part of the sport’s allure.

“You only get better if you’re putting yourself at risk sometimes,’’ said Nate Eisenheim, 19, McGuinness’s friend. “If you want to progress, you have to do stuff that scares you.’’

McGuinness added a caveat. “After a good day skating, everything hurts,’’ he said. “Everything but your head, if you’re lucky.’’

Only the very youngest and very oldest skaters at Lynch wore helmets or padding on a recent afternoon, trading cool for caution.

Eisenheim and McGuinness met their first day of college orientation at the University of Massachusetts Lowell when McGuinness approached Eisenheim after seeing his skate-shop hat. Before classes started, they came to Lynch. A year later, they still meet here to skate.

“Nate’s a good skater, and also probably the best skate coach I’ve ever had,’’ McGuinness said. “When I am doing something wrong, he tells me how to fix it.’’

The two friends agree Eisenheim is clearly the superior skater, a fact that causes no friction in their friendship. Each comes to practice his own footwork, more parallel play than competition.

When one does well, the other whoops or whistles. Webber also calls out to his other friends.

“Yo, you’re fire!’’ Webber called out to one who had just landed a challenging jump. “That was gnarly, go right in.’’

Few women skate regularly at Lynch, Webber said. Only one sat on the side, Frances Penney, 18, who came in a knee brace with McGuinness and Eisenheim. But she wouldn’t have skated anyway, even though she knows how. She stopped as a child when she didn’t receive encouragement.

“My brother was the only one who would be like, ‘Oh, you got it,’ ’’ she said. “I wish I hadn’t stopped.’’

Usually, skaters encourage each other, but tensions can flare. About a week ago, the skaters said, one skater punched another in the mouth and broke his jaw, all because he didn’t stop a runaway board.

When the park is crowded on weekends with children and families, frustration can mount as skaters try to find room for their moves.

“We got a little feud, skaters and scooters normally,’’ Eisenheim said, watching a scooter rider jump over railings and skid to a complete stop. “But that kid is really good.’’

“That kid is too talented to be mad at,’’ McGuinness said.

The two rested, their sweat heavy in their T-shirts, boards by their feet. They watched the skaters glide past, their bodies bending and curving in the summer air.

Contact Amelia Nierenberg at amelia.nierenberg@globe.com.