Along with 17 other riders, they will form Team Charlie to raise money for Muscular Dystrophy WA at the annual Dwellingup100 mountain bike ride, about 100km south of Perth.
Steven and Jodie Hughes will also ride for Team Charlie in dedication to their five-year-old son, who has muscular dystrophy and has never walked.
Aube and Millen, both from Wembley Downs, said the team aimed to raise $20,000 for the Ride for Someone Who Can't.
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READ NOW"Team Charlie is at $16,000, so we're close to our goal," Aube said.
Aube will cycle 100km in his third Dwellingup100.
"The downhill section is quite technical," he said.
"It's a great challenge."
Millen is also riding for his third time.
"I love getting out in the bush and getting some exercise," he said.
Swanbourne resident Young said she got involved with Team Charlie after meeting Charlie's parents through mutual friends.
"Charlie is cute and cheeky and just like all other boys, he wants to eat naughty foods," she said.
"Im honoured to be a part of Team Charlie."
Muscular Dystrophy chief executive Hayley Lethlean said she would ride for the first time among 61 people who would cycle 14, 40, 65 or 100km this weekend.
"I bought my first mountain bike this year and I've done about six off-road rides, but I do a fair bit of exercise so I think Ill be OK," Hayley said.