Day One: Pan Mass Challenge Riders Share Their Stories

BOURNE (CBS) -- They started out early Saturday morning, and then it started to rain. But thousands of cyclists didn't let the rain slow them down.

Rider Stephen Waisgerber says that the course itself has some incentives to keep going.

"You come in and about a mile out are a set of pictures of all of these little kids going through treatment right now and that makes the rain a little less imposing," Waisgerber said.

The cowbells were ringing and the crowd was upbeat as riders made their way to the Pedal Partners tent in Lakeville.

This is Jason Steiner's very first Pan Mass Challenge. He's always wanted to ride the PMC, but it wasn't until his daughter, Olivia, was diagnosed with cancer that he decided to take part.

"You're faced with some news that no parent should have to face and our world changed," Steiner said.

Steiner's daughter Olivia is a bit camera shy - but the four year-old is certainly resilient. She was diagnosed with leukemia the day after her second birthday.

Her mother Olivia says that her family had a rough time seeing Olivia have to endure chemo therapy.

"It was really grueling. I mean she had a tough time, obviously chemotherapy with a small child. It was hard on the other kids to see their sister suffer," Christine said.

Olivia's one of more than 100 Pedal Partners this year. These are kids battling cancer at the Jimmy Fund Clinic who are paired with PMC riders to raise money for cancer treatments and research. She's living proof of what each dollar - each donation can do.

"She just, a week and a half ago got her last chemo, so we're so happy to be on the other end of it," Christine said.

Thousands of cyclists pedal their hearts and souls out for this special. And tomorrow - many of them will hop back on the bike for Day 2.

The challenge ride goes all the way to Provincetown.

So far, over $140,000 has been raised.