William “Kim” Flint II was speeding down South Park Drive on his bike June 19 in an attempt to regain his speed record that had been broken by another rider five days earlier, when he skidded into an oncoming SUV and suffered fatal injuries. He was 40.

Flint, an Oakland resident and sound engineer, was taking a wide turn on the road in Tilden Park and drifted into the oncoming traffic lane, according to Lt. David Dubowy, watch commander at the East Bay Regional Park District Police Department.

“He skidded into the left side of the car, and ricocheted off,” he said. “That was when he fell from the bike and crashed.”

Witness statements and Flint’s GPS at the scene suggest Flint was going more than 45 miles per hour down the hill, according to Dubowy.

From June 6 to 14, Flint held the record for the fastest descent time – an average of 39.9 miles per hour – on South Park Drive, on Strava.com, a social networking site for cyclists that provides “detailed analysis of all your rides … based on your GPS data,” according to the website.

On June 15, another cyclist pulled ahead of Flint in the rankings for South Park Drive with an average time of 41.2 miles per hour.

Violet Hefner, Flint’s partner of 19 years, said she is “99 percent certain he was trying to regain his lost record,” the day he was killed.

Hefner said they had originally started cycling together, but she thought it was too dangerous.

“He knew that I was very, very afraid of him riding on city streets,” she said. “I begged him not to.”

Hefner added that once Flint joined Strava, his interest in his speed and his ride statistics became more intense.

“Things really escalated once he got involved with Strava,” she said. “It became an obsession with him.”

Flint holds a best time of an average of 33.9 miles per hour on the “Centennial Drive Descent” in Berkeley as well as the record for the “Skyline Boulevard Descent” in Oakland with an average of 30.4 miles per hour.

Hefner said Flint had been focusing more and more on getting “king of the mountain” – the highest speed for a certain stretch of road – for downhill segments over the last two months.

Hefner added that though the website fueled Flint’s urge to push himself, she didn’t blame the competitive nature of Strava for his death.

“They’re trying to do something to help motivate people. I think that’s a good thing,” she said. “(Kim) did frequently push himself to his limits … in this case, his limit was not a good thing.”

According to Bill Sparks, a mechanic at the Missing Link Bicycle Cooperative in Berkeley, the segment of South Park Drive approaching Grizzly Peak Boulevard is one of a handful of hills in the East Bay where bikers can and do reach speeds of 50 miles per hour.

Sparks said he does not try to reach such speeds these days, but he recalled coming close on a ride 25 years ago.

“My speedometer said 48 miles per hour,” Sparks said. “I was hanging on for dear life.”

Sparks added that regardless of traffic, biking at a speed of 50 miles per hour is inherently dangerous.

“The way the bike handles at that speed is different,” Sparks said. “Your back wheel’s jumping around behind you … those little undulations (in the road) will send your bike flying.”

Red Sun Soundroom, a New York music studio that Flint worked with, posted a special tribute to Flint on its website.

“Kim Flint was an inventor, musician, internet community organizer, scientist, avid cyclist, single-malt Scotch enthusiast, teacher, and tireless provider of encouragement to so many creative people,” the site reads. “The Red Sun Soundroom would be nothing like it is – and perhaps it might be nothing at all – without Kim Flint.”

An unofficial service for Flint was held Friday at Heinold’s First and Last Chance Bar in Oakland. Hefner said she was proud of him for all he achieved.

“We were two halves of a whole,” she said.