Biking is one of the most enjoyed athletic and recreational activities in the country — a full 33% of Americans stated that they ride bikes for fun. And now, it’s a subject of interest for many shoppers and Robin Williams fans, after 87 of the comedian’s bikes were put up for auction earlier this month.

Most people remember Robin Williams for his sense of humor and talent onscreen, but not many people knew that he was an avid bike enthusiast.

The bikes were donated by the Williams’ children, Zak, Zelda, and Cody, almost two years after his suicide. The proceeds from the auction will go to the Challenged Athletes Foundation and the Christopher and Dana Reeve Foundation, both charities that Williams cared about and donated to during his life.

“Though bright, skin-tight spandex still remains one of the more embarrassing outfits to regularly witness your Dad wearing growing up, the sport of biking and the people Dad helped through his love of it will always hold a special place in the hearts of our family,” said the Williams family in a statement.

The collection is on Paddle8.com, and the auction will run online until 1 p.m. ET on October 25. The collection includes a number of luxury racing bikes, along with some novelty items, like a “Runt” mini bike, a Schwinn unicycle and a Z turbo-electric scooter.

The auction could bring up to $200,000 to the non-profits. Peter Wilderotter, the CEO of the Christopher and Dana Reeve Foundation, which funds research for people with spinal cord injuries, said that Williams supported them “without fanfare.”

Similarly, the Challenged Athletes Foundation, which issues grants and support to disabled athletes, said that the Williams family were “fixtures” at the organization’s fundraisers and events.