For Klein, a 66-year-old Philadelphia Orchestra violinist, the 513-mile ride has combined passion and compassion. It's a testament to his love of cycling and physical fitness. It's a tribute to MS patients, particularly the late British cellist Jacqueline du Pré, regarded as one of the greatest players of the instrument, whose career was cut short by the disease. And it represents Klein's personal triumph over anxiety and self-doubt.
"What has the bike done for me?" asks this self-described "professional worrier." "Everything. It has been my savior, and made me fit to live with."
Klein has been performing with the orchestra for 40 years. Before that, he played with the Detroit Symphony Orchestra. His mother was a music teacher who put a violin in his hands when he was 31/2. For most of his adult life, he was so devoted to music that he rarely exercised.
"There was never any time," he says. "I was always hustling to one rehearsal after another."
When he and his wife, Gisela, moved to Philadelphia in the early '70s, they sometimes cycled the river-drive loop, but those rides were purely casual and recreational.
In 1986, Klein served as chairman of the orchestra members committee. He was fixer, confessor, troubleshooter, flak-catcher. "I listened to everybody's problems. It sometimes took 40 minutes to get from the stage door of the Academy [of Music] to backstage. Everybody was after me."
It was a job that required "King Solomon solutions to lots of difficult issues," a job so stressful it nearly killed him.
During one sleepless night, while walking his dog at 3 a.m., he began feeling chest pains and tingling in his arms - classic symptoms of a heart attack. He was a prime candidate - 51 years old, a smoker who drank 20 cups of coffee a day.
Luckily for Klein, the attack turned out to be more psychosomatic than cardiovascular. Nevertheless, what Klein calls "the stress crash" took its toll.