Courtesy of UC Berkeley Police

MIchael J. Vandeman complains that mountain bikes destroy wildlife. Bike activists say he just hates mountain bikes.

Michael J. Vandeman has long had a thing about mountain bikers.

For more than a decade the Berkeley resident has been railing against them in Internet chat rooms and on environmental and bicycling websites. He maintains a number of websites where he complains that mountain bikers destroy important habitats and should be banned. He calls them one of his “peeves”.

Vandeman’s vendetta seemed to be a verbal one. Until recently.

UC Berkeley police arrested Vandeman, 67, on May 28 after he allegedly used a handsaw to attack a bicyclist on a fire trail above the UC Berkeley campus. Vandeman also allegedly confronted another bicyclist in the same area in the summer of 2009 and used a sharp tool to puncture his tire. Vandeman was arraigned Wednesday and is being held on $12,500 bail in the Oakland city jail.

“This guy is a well-known kook in the mountain biking community,” said Brent Englund, president of the Bicycle Trails Coalition of the East Bay. “He has spent years and years railing against mountain bikers.”

Vandeman would spend hours on the Internet writing negative comments about mountain biking, said Englund. If someone posted a comment on a chat site, Vandeman would often call up that person’s boss and suggest he be punished for going on the Internet on company time. Vandeman was so persistent that he became known as a “troll,” or someone who deliberately tries to mess up Internet conversations, said Englund.

Vandeman’s emails were so prevalent that the Evergreen Mountain Bike Alliance in Washington even created a Web page to explain who he is and what he did. Here's an excerpt:

Q: What exactly is the point to Mike Vandeman’s posts?

A: He hates mountain biking, and wants it banned. It conflicts with his desire to hike on trails he wants to himself. He doesn’t want you mountain biking past him when he’s hiking, and really gets pissed when it happens on a hiker only trail. … [H]e thinks all mountain bikers are destructive, and behave the same. It’s bigotry, plain and simple.

Despite Vandeman’s history, Englund does not think he is dangerous or even that he meant to attack a bicyclist with a saw. He thinks Vandeman probably grazed the bicyclist accidentally.

“I don’t think he jumped out from the bushes and tried to hurt someone,” said Englund.

Still, many mountain bikers are relieved at Vandeman’s arrest. A number of them attended Wednesday’s hearing, where Vandeman was charged with misdemeanor vandalism for the 2009 incident and misdemeanor assault for the 2010 incident.

The incidents both took place on the upper section of the fire trail that runs from Grizzly Peak Boulevard to Strawberry Canyon, east of UC Berkeley's Memorial Stadium. Hikers are allowed on that trail; bikers are not.