Aucklander Rosie Garner, 60, and her 70-year-old husband John, have ridden in the event since it began in 2011.
"It's been great this year because we've never biked in the south direction before, and I like the fact it gets you on your bike," Mrs Garner said.
The event's new shorter routes opened up the event to many more youngsters, like 12-year-old Ethan Griffiths who joined his grandfather Hugh, who was delighted to be able to take part with his grandson this year.
"It was fun, really cool, especially going down the bridge, but the up was a bit challenging," said Ethan.
Thousands took the opportunity to bike the bridge both ways for the first time. Photo / Supplied
His 71-year-old grandfather added: "We got a bit of practice in beforehand and cycled a couple of hills as training for this."
Levi Matthews, Brayden Thompson, Jayden Williams from Arahoe School in west Auckland, were on unicycles with their teacher Megan Connolly.
"It was really cool, but it did hurt. We trained hard for this and it only took us 45 minutes," said 11-year-old Levi.
The event was manned by 300 volunteers who act as marshalls along the route.
Westlake Boys High School student Chris Munroe was on the bridge at 5am to marshall the cyclists and help raise money for the school's cycling team.
"It's a good way to help out the club and it's not often you get to stand at the top of the Harbour Bridge," he said.
"You can really appreciate how much goes into making events like this happen, just seeing how much has gone into getting the buses in place to line the route," he said.
More than 100 commercial buses were used as a safety barrier between the motor vehicles and the cyclists.
"We started moving the buses at 9.30pm last night and we've moved at least six buses each and got them in place ready for the 6am start," said Ritchies Coachlines bus driver Nick O'Sullivan.
This year's family friendly format attracted a variety of different bikes. Photo / Supplied
"It's the first time I've ever done this and it's been really enjoyable. It's colossal setting it up, everything has to be coned off before we can even start parking up."
Bike the Bridge raised thousands of dollars for the Multiple Sclerosis Society.
Organiser Callum McNair was delighted that so many people took up the challenge.
"It's been a fantastic morning and it was great to see such a huge variety of bikes out there on the bridge," he said.
"The new format has been really popular and the feedback from the families who took part has been extremely positive."
