Lafayette parent Julie Marshall wanted an adaptive bike for her 13-year-old daughter, Sarah, so the family could go on rides together.
She started searching online for custom adaptive bikes that could work for Sarah, who is on the autism spectrum and has sensory processing disorder and limited motor skills. She also loves to play outside.
Marshall found a company that builds adaptive bikes, but charged a way-out-of-budget $6,000.
"That's a car, not a bike," she said.
So she kept searching, turning up an engineering student in another state who had built a four-seater adaptive bike. Thinking to find a local engineering student, she reached out to CU and was connected to Mindy Zarske, an instructor for the Engineering Plus program.
Zarske promised to include the idea as a possible project for her Engineering Projects for the Community classes, and it caught the interest of one of the student groups.
The six engineering students, a mix of sophomores and juniors, spent the past semester building a custom bike for Sarah.
"I felt like I won the lottery when they picked our project," Marshall said.
The adaptive bike recently won the people's choice award out of 200 projects at CU's engineering expo. They're still making a few adjustments to the bike to make sure it's sturdy, then plan to give it to the Marshalls in January.
Only one student on the team had a background in mechanical engineering, but the students said they learned as they went.
"It was a very big learning experience," said junior Alex Helsley.
The students started by meeting Julie and Sarah at a park so they could get to know Sarah, then met with her physical and occupational therapists to learn more about her specific needs.
They built a prototype, found a company — EMJ Metals — willing to donate the steel for the frame and took a welding workshop. Finally, last month, they started the welding and assembly. The complex welding took more than 100 hours, with the students devising a "fish mouth cut" to connect the steel tubes.
"It's a lot of work to do in a semester," Helsley said.
The three-wheeled bike is a two-seater — the seats came from a race car company to provide extra back and neck support — with a joint handlebar. There are also seat belts for extra safety.
"Sarah is capable of riding," sophomore Lauren Kercheval said. "She might just need a little extra help."
Then there are the extra touches.
The bike is purple, Sarah's favorite color, and plays her favorite songs — "Twinkle, Twinkle Little Star" and "You Are My Sunshine" — as she pedals to motivate her to keep going.
Junior Brooke Lynn Elzweig said the bike is designed to provide both physical and social benefits, including improving fine motor skills and communication and helping Sarah get out in the community.
The students said they liked putting engineering theory into practice and working on a community project. The other three students who worked on the project were Jack Berg, Blayne Robinson and Elijah Gonzales.
"It wasn't just math and science," Elzweig said. "It made us think about the greater good and engineering to make the world a better place."
Marshall said she's thrilled with the end product.
"It's amazing," she said. "It looks exactly like the prototype. They really got to know Sarah and made a bike super specific to her."
Once they have the bike, Marshall said, she expects they'll use it often on trips to Lafayette's Waneka Lake. She said biking is also something Sarah and her 11-year-old sister, Jazzy, can share.
"It's the best gift," she said. "I just can't thank the students enough. They're such creative, positive people. It gives me a lot of faith in the future."