"It definitely pushed you very hard," said Muensterman, a 17-year cycling veteran who races for Capoforma cycling apparel. "It was a very difficult race and a lot of bigwigs came out."

Part race, part obstacle course, the cyclocross brought hundreds of spectators to Galvin Park in Santa Rosa to watch a total of seven races, with professional cyclists competing in the day's finale.

The inaugural event kicked off a long weekend of bike racing in Sonoma County that will culminate with the finale of Stage 1 of the Tour of California on Monday.

The day had a serious side, too.

It marked day one of a three-day fund-raising effort to generate money for Sister Shop, a nonprofit program to establish bike shops in Africa to help maintain the thousands of bikes that have been donated for use as an economic tool in impoverished nations.

"It's just something minor that we can do on our part to help with something major over there," said Jim Keene, general manager of NorCal Bike Sport in Santa Rosa, a co-sponsor of the fundraiser.

Along with its local partner shop, The Bike Peddler, NorCal is teaming up with BikeMonkey magazine to raise $5,000 to establish a shop in Butare, Rwanda.