More than 300 people, including the children's mother Katharine Webb, dressed in colourful clothes and with balloons attached to their bikes and helmets rode from Forsyth Barr Stadium to St Leonards and back in the Ride to Remember.
Bradley (9) and Ellen (6) were shot and killed by their father Edward Livingstone in St Leonards last month.
Ms Webb took part in the ride with two balloons, one pink and one blue, attached to her bike.
Organiser Kashi Leuchs said Ms Webb's attendance was ''wonderful'' and for her to see the tribute was ''the biggest thing we could ask for''.
He was pleased with the response from the community.
''It really indicates that people want to do something,'' he said.
''It's wonderful. It really shows that Dunedin has a heart.''
The colourful theme of the ride was designed to get children smiling and to pay tribute to Bradley and Ellen, he said.
''People want to show their respects and they were colourful kids,'' Mr Leuchs said.
Mayor Dave Cull, who also took part in the ride, said the turnout was ''an indication of how much the deaths of Bradley and Ellen touched the hearts and minds of Dunedin''.
''This bike ride is one of the ways we can show we care,'' he said.
''It's also an attempt to rekindle the lost joy of Bradley and Ellen's schoolmates.''
St Leonards School board of trustees chairwoman Ceri Warnock said most of the community had turned out to show their support.
''The teachers are all here on their bikes. It's great. It's just nice to have something so positive for the kids,'' she said.
Funds were raised at the event to go towards the community, but St Leonards School principal Jo Wilson said the gesture was worth more than the money raised.
''The money isn't the important thing. It's the fact that some people got up off the couch because they cared and did something,'' she said.
''That's the cool part and that's what we are going to remember.''
An auction to raise funds for the community, organised by school alumni, had raised more than $6000 by yesterday afternoon.
