They usually spend their free time climbing any rocks they can find, but you might recognize them as those people who seem to walk on a tightrope across the quad and near Allen Hall.

They’re actually not training for the circus – they’re slacklining.

“It’s like a tightrope but not,” said Clay Karz, freshman in LAS. A long, durable piece of rope called tubular webbing is all that stands between the slackliner and the ground.

“There’s a lot of slack in a slackline, hence the name,” said Kevin Brown, a second-year graduate student in aerospace engineering. The difference between a tightrope and a slackline is that the tightrope is strung so tightly that there is no give in the line, while a slackline might sink close to the ground.

“It’s only one line, but a lot of crap is used to get it tight,” Karz said, using a car as an example. To pull the line extra tight, one end was hooked up to the back of a car.

Karz and Brown both climbed before exploring slacklining. The activity helps improve balance and control of the body, which comes in handy when climbing rocks or simply trying to cross a one inch wide rope.

“It’s fun. I’ve done it a few times,” said Kim Palka, freshman in LAS. Though many people come to check out what Brown, Palka and Karz do, few stick around long enough to get better.

“We show a lot of people how to slackline on the quad,” Brown said. “It’s not just like riding a bike. You just gotta be a dedicated slacker.”

“You can learn it so quickly but unfortunately you can lose it just as quickly,” Karz said.

Slacklining is one of a few tangent activities related to climbing. Others include a technique based climb called bouldering. Bouldering does not use a rope but stays relatively close to the ground. The strength and power needed to boulder help a climber to solve problems in routing a climb. Usually bouldering is more difficult because it is lower and shorter than regular climbs.

“It’s a short climb – like a sprint. Real climbing is more like endurance,” Karz said.

Buildering is simple bouldering on buildings, and the extreme variant on climbing is highlining. Highlining is a slackline that is far from the ground sometimes 200 feet. People can highline with a safety rope for extra protection and people have highlined over canyons.

“We don’t endorse these activities,” Brown said of buildering and highlining. These members of the UIUC Climbing Club stick to climbing, bouldering and slacklining.

To start slacking, some equipment is necessary. A one inch thick set of tubular webbing, the rope used for slacklining, is a must. Other pieces include clips called carabiners and something to attach the slackline to.

“Basically anywhere where trees are within 35 feet of each other,” Brown said.

Some slacklining kits can also be purchased. They range from $30 to $200, depending on what type of equipment is needed.

“If you’re unfamiliar to climbing, investing in a kit would be a good idea,” Karz said. “It’s a very meditative and focused thing … If you got problems, go slacklining.”