A little while ago, Kevin O'Sullivan, the affable president and chief executive of Massachusetts Biomedical Initiatives, decided to bet his friend Paul J. Curley that he would beat him in the third annual George Street Bike Challenge for Major Taylor this month.

Mr. Curley, a 49-year-old Taunton resident, accepted.

George Street is one of the steepest roads in the city. It's about 500 feet long and runs from Main Street to Harvard Street.

With dinner on the line, Mr. O'Sullivan began to train and pick out his bicycle equipment.

Visiting a yard sale, he picked up a helmet for $3 and "modified" his 14-year-old daughter Kylle's mountain bike by adjusting the seat.

Worcester Diary doesn't know what kind of equipment Mr. Curley will use but can guess who's the David and who's the Goliath in this challenge.

Mr. Curley is a national cycling champion. He holds the masters national criterium title for men ages 45-49, and he placed first in the masters division of the recent Hartford Downtown Criterium.

He knows Lance Armstrong, the guy who's won that fancy race in France five times and is a favorite to clinch a record sixth victory on July 25, the same day as the George Street time trial.

"Yeah, I think he might have some advantage," Mr. O'Sullivan admitted.

Mr. O'Sullivan and Mr. Curley became friends through their wives, who were classmates at the University of Massachusetts.

The couples often have dinner together.

Despite their friendship, Mr. O'Sullivan hopes to do his best to upset his friend.

He's been riding his daughter's bike around the city and has tried climbing George Street four times.

Mr. O'Sullivan, who's going to be given some kind of handicap, said he got dizzy and almost passed out the first time he tried.

Still, Mr. O'Sullivan is no slouch and he has a chance.

An avid runner, he hits the streets five times a week for a few miles and has competed in many road races, including the Boston Marathon.

"I do know one thing," Mr. O'Sullivan said. "I plan to retire from competitive bike racing the day after the George Street Challenge."