San Francisco -- It’s possible Robin Williams loved bicycles as much as anyone has ever loved bicycles. The late Oscar-winning actor is best remembered for his relentless comic energy and films like “Mrs. Doubtfire” and “Good Will Hunting,” but away from the public eye, Williams was an obsessive cyclist who found joy and camaraderie in the sport, and was often seen pedaling the roads near his Bay Area home atop one of his many colorful rides.

As bike collections go, Williams’s is legendary. It contains everything from carbon-fiber Tour de France racing bikes to wildly-painted custom builds to outrageous, one-of-a-kind machines. There are single-speeds, a chopper, a Rube Goldberg-like indoor trainer, and a unicycle, naturally. At its peak, Williams’s collection numbered more than 100 bikes, an eccentric and encyclopedic stable that in many ways reflected the comedian himself.

“He had such a passion for the sport and the bicycle,” said Williams’s friend Jim Ochowicz, a former elite rider who manages the pro BMC Racing Team. “He loved the colors, the design, the engineering. When I rode with him, he’d often be on another bike, and I’d be like, ‘Whoa, where is that one from?’”

Now Williams’s collection is going up for sale to the public. On Thursday, October 13, the online house Paddle8, in conjunction with Williams’s family, began auctioning off 87—yes, that’s eighty-seven—of Williams’s bikes to benefit a pair of charities that were close to the actor: the Challenged Athletes Foundation (which promotes sports and active lives for people with physical challenges) and the Christopher and Dana Reeve Foundation (focused on curing spinal cord injuries and improving quality of life for people with paralysis).

Earlier this month, I got a tour of the collection at an art space south of downtown San Francisco. Cyclist and photographer Justin James King, who cataloged the bikes, guided me through a series of rooms containing Williams’s rides, which he had meticulously examined and photographed for the sale (the bikes were very well kept; and most of the stock frames are sized around 54 cm).