More than 500 bikes are expected to roll into town Sept. 20 for the 13th annual Rick Graham Diabetes Awareness Memorial Ride.

The ride is held in memory of former Boston firefighter Rick Graham who suffered a diabetic coma while riding his motorcycle in 2001.

Organizer Deneen Rose said the event has ended at the Dudley L. Brown VFW post in Onset since 2009.

“At that time I was a bartender, and I was overwhelmed by all the bikes,” Rose recalled. “I sat down with a few members and told them there were a few businesses here that would be happy to help.”

Rose said the event has since grown from between 200 and 300 bikes to almost 600 bikes. She said she expects between 500 and 600 bikes this year and has around 40 volunteers helping with the event.

“They start at 6 a.m., and [work until] 6 p.m.,” Rose said of the volunteers’ dedication.

Rose said the bikers ride 50 miles of back roads from Dorchester to Onset. Half of the money they raise is given to the American Diabetes Association and the other half is used to help former bikers’ families.

Rose said the event is still looking for more sponsors. Businesses that give $150 or more will get their names on T-shirts that will be available for purchase.

Registration will take place Sept. 20 at 11 a.m. at the Boston Firefighters Union Hall, 55 Hallet St., Boston. The donation fee for a rider and a passenger is $20 in advance and $25 at the door. Children 12 and under ride for $10. There will also be a 50/50 raffle, music and food. The event’s rain date is Sept. 27.

For more information, contact Adrian at 617-293-7039, Rick at 617-877-2155, LaCarl at 617-866-7217, or e-mail rickgrahammemorialride@yahoo.com.