On the weekend leading up to the 18th anniversary of the September terrorist attacks, Susan Retik rode her bike from the Ground Zero memorial in New York City to her home in Boston. 

She was joined by 35 other cyclists, each of whom had pledged to raise at least $3,000 for charitable organizations before signing on for the three-day, 260-mile ride.

It was just one example of the cycling community coming together to mark today’s somber milestone.

Retik’s husband David was killed on flight 11 during the World Trade Center attacks on September 11, 2001. In the years after, she co-founded Beyond the 11th, an organization that raises funds for Afghan women who were widowed in the subsequent U.S. invasion, a cause Beyond the 11th describes as fighting hate with compassion.

“I think everybody does the ride for different reasons,” Retik told Rad Power Bikes Wednesday. “It’s my way of raising money, using my voice on behalf of the women who really need it, who are more voiceless, and doing it around 9/11.”

Retik’s ride, known as Beyond the Bike, is one of the organization’s key fundraisers. An event that started in 2004, this year’s ride up netting $170,000.

And it’s not just Beyond the Bike that’s encouraging cyclists to pedal for a cause.

Also on Wednesday, another set of cyclists completed a two-day, two-state trek from the Pentagon in Arlington, Virginia, to the Flight 93 Memorial outside Shanksville, Pennsylvania.

Dubbed the 9/11 Promise Bike, participants rode nearly 200 miles to honor those who lost their lives in the wake of the tragedy and to raise scholarship funds for military and first responder families.

The ride coincided with the 9/11 Promise Run, a similar challenge that saw runners tackle a 3-day, 250-mile journey from the Pentagon to Ground Zero in New York City.

Retik said that she’s not surprised to see so many people in the cycling community attempting to make a difference, noting that cyclists are, in her words, “the best people.”

“As a cyclist, you get it,” Retik explained. “We have this amazing group of people where I live, and we train together. We all support each other however we can.”

To support Beyond the 11th, you can make a donation here.