After Lance Armstrong Twittered his plans to return and Sacramento Mayor Kevin Johnson promised to keep everyone's bicycle safe, two questions rode to the front of the Amgen Tour of California pro cycling race Thursday.

How will a move from February to May affect the quality of the field?

And what kind of route will race officials come up with for the 2010 first stage from Nevada City to Sacramento?

Nevada City was one of four new cities added for the fifth annual race, which is scheduled to begin May 16 with a stage from the foothills community to Sacramento.

Plans call for a stage 2 start in Davis that finishes in Santa Rosa on May 17. The eight-day event will include a stage 6 mountaintop finish in Big Bear Lake and an overall concluding stage in the Thousand Oaks/Westlake Village/Agoura Hills area.

When official word came that the race would begin in Nevada City, a packed house in the City Council chambers stood and cheered, according to City Manager Gene Albaugh.

"We were really excited today," said Albaugh, whose city has hosted the Nevada City Classic bicycle race for 49 years.

Sacramento's performance in putting on stages in 2007 and 2008 and a prologue last February left little doubt it would remain a host city.

"Never failed to have a great day," said Andrew Messick, president of AEG Sports, which owns and operates the Tour of California.

Well, there was that incident where Armstrong's $10,000 time-trial bike was stolen last year from a team van parked in downtown Sacramento. The bike was recovered a few days later.

The mayor good-naturedly went on the offensive during a press conference Thursday afternoon in Old Sacramento.

"We are going to make sure that everyone's bicycle is in good hands," Johnson said. "Please bring a lock just in case."

The move of the U.S. Bicycling Hall of Fame to Davis earlier this year likely helped that city's bid.

"I hope that was taken into consideration," said Davis spokesman Bob Bowen.

The 2009 race attracted a talented field that included Armstrong, a seven-time Tour de France champion, three-time Tour of California winner Levi Leipheimer, 2008 Olympic champion Fabian Cancellara and 2008 Tour de France winner Carlos Sastre.

But the move to May puts the Amgen race in competition with the well-established Giro d'Italia, a three-week race around Italy for the world's top riders.

Messick said the move was made to ride in better weather and showcase more of California.

"Shifting to May will open up the Sierra Nevada and various mountaintops and areas like Lake Tahoe," he said.

Leipheimer, who plans to ride in the 2010 event, said the Tour of California is a better training ground than the more-demanding Giro d'Italia for the Tour de France, which is set for July 3-July 25.

"There's so many racers," he said. "Both races are going to see a great peloton."

Messick said he's confident the Tour of California will attract another quality field.

"There are certain riders who aren't going to want to do 20 days, 20 hard days," he said. "For those riders who feel that it's more appropriate to have eight good days, a block of training, I think that we're an ideal alternative."

Race officials said route specifics wouldn't be revealed for several weeks, leading to speculation on several stages, including the opening one.

Albaugh suggested a route to Colfax including Rattlesnake Road or Highway 174, a climb to Foresthill, a drop down to Auburn and a trip down Auburn-Folsom Road to Folsom before heading to the finish at 11th and L streets.

Michael Sayers, a longtime pro cyclist from Sacramento who serves as an assistant director for the BMC Racing Team, said there were several good possibilities.

"Ideally, they'd like to see a bunch finish," he said. "There's a bunch of small roads up there. They can weave back and forth, through and across (Highway) 49.

"I think it really would be great to incorporate those communities of Auburn and Folsom."

Messick also said going through Auburn and Folsom would be a positive.

The Sunday start should give Sacramento officials a chance to stage a weekend cycling festival that could surpass what they did for the February prologue, Sacramento Sports Commission Executive Director John McCasey said.

An estimated 70,000-75,000 spectators attended the prologue, with the Sacramento Convention & Visitors Bureau estimating the economic impact at $8 million.

McCasey said Armstrong's return and a regional route for the first stage could attract 40,000-80,000 fans.

"That's huge," he said of Armstrong's commitment. "We're off to a good start."

Call the Bee's John Schumacher, (916) 326-5523.