Hemonds’ Minot track has become a destination in New England MotoCross.

LEMPSTER, N.H. – Still wearing his back brace, Norm Hebert stood alongside his son, James, 6, ready to send him off on part of the same motocross course where he broke his back six weeks earlier. Daughter Danielle, 8, was waiting to ride in the next race.

“My kids were here when I got hurt,” said Hebert, of Mansfield, Conn., as they waited for the start. “It didn’t faze them a bit.”

A few rows farther back, waiting for his race, was John Nolan of Granby, Conn. At 54, he races every weekend. His son, who is 23, also races, and his grandson, who is 1, will be racing one day, Nolan says emphatically.

The Heberts and Nolans are part of a phenomenon: two and even three generations of families

speeding around dirt tracks and hurtling off jumps at weekend motocross races that are a growing attraction around rural America.

Motocross is run on small motorcycles on natural terrain with man-made obstacles. About one-third the weight of a motorcycle, the bikes have special suspensions and knobby tires for traction through dirt and mud.

Motocross boomed in the late 1970s and early ’80s before running out of gas, said Tom Lyons of the New England MotoCross (NEMX) series. Probably spurred by extreme sports on television, a resurgence began around the mid-1990s.

Participation in amateur motocross events sanctioned by the American Motorcycle Association increased from 191,280 in 1992 to 476,654 in 2002, spokesman Tom Lindsay said.

Racers reach speeds of 50 mph and can get 20 to 25 feet off the ground in jumps that can carry them more than 100 feet. The dozens of jumps in a typical race, perhaps six miles, include “tabletops,” “doubles” and “whoops.”

But thrills and trophies aren’t the only draw.

“It’s a family weekend,” says Kathy Burdick, whose family traveled two hours from Berlin, N.Y., in a converted school bus on a recent weekend to the Jolly Roger track in Lempster.

She and husband Joe watch sons Aaron, 7, and Kyle, 5, race, and bring daughter Hannah, 4, for the fun.

“The kids meet friends and they get to travel all over,” she said.

Kathy and Joe also have made friends whom they see almost every race weekend.

Marie-Claire Ford drove two hours from Monson, Mass., with racing son Matthew, 13, and daughter Meghan, 11, in the family’s $55,000 mobile home, bought partly for motocross weekends. (Husband Harold had weekend military duty and couldn’t make it.)

“I don’t ride, my husband doesn’t ride, but it’s a family thing,” Ford said. “That’s what I like about it.”

On this particular Saturday, there were 43 races in about 21 classes for almost every age, part of a traveling series put on by New England MotoCross.

About 600 racers, parents, relatives and friends swelled the crowd to more than 1,000. But there have been Saturdays twice as big, owner Marco Gagnon said.

Mobile homes, vans and trucks squeeze into every available space around the sprawling, dusty, dirt track, many arriving Friday night to get a parking place for Saturday’s races.

The scene is played out at tracks throughout the country. In the Northeast, there are tracks in Southwick and Middleboro, Mass.; Walden, N.Y.; Derby, Vt.; Winchester, N.H.; Greene and Minot, Maine; and Central Village, Conn.

Gagnon bought the Jolly Roger property, a farm, in 1994 and opened the track in 1996.

“I went through every bank up here and they all laughed at me: ‘Nobody is going to come to Lempster,”‘ he said.

But one bank didn’t laugh, and the track has been riding a wave of popularity ever since.

There are concerns.

“Call any physician in Keene and ask them, and they would give you an earful,” said Dr. Michael Sarson, a radiologist at Cheshire Medical Center in Keene.

“What I was seeing is truly appalling … injuries that you’d expect from a high-impact highway collision,” he said.

“We have little children driving motorbikes far too heavy for them. This is something truly over the edge in the degree of danger,” Sarson said.

Sarson said he would not object to motocross if it were made safer.

Serae and Donald Hemond tried. They built their own commercial track in Minot, Maine, to provide a safe place for son Michael, 18, and other area kids, to ride.

“There were so many kids around here that have dirt bikes, and outside of riding in the woods and bouncing off rocks and trees and being on other people’s property, they had no place to go,” Serae said.

“It’s a very dangerous sport; we try to keep it as safe as we can and still let them get the air they want,” she said. “Air” is motocross lingo for time spent airborne during a jump.

Broken bones are common, and worry parents like the Burdicks and Fords. But they come to accept it.

“You can’t discourage them if they want to do it,” Kathy Burdick said. “The best you can do is get all the protective gear.”

That means body suits, helmets, chest protectors, boots, gloves and goggles, which can cost hundreds of dollars on bikes that start at about $1,000 used.

The Fords’ son has separated both shoulders and broken a collarbone, but “it didn’t slow him down; it didn’t stop him at all,” his mother said.

“I tried diverting him to other sports; I tried baseball, soccer, golf,” but none worked, she said.