The 28-year-old who was killed by a bus outside the Olympic park tweeted about his love of cycling and how bike riders who jumped red lights "give the rest of us a bad name."
Dan Harris also tweeted about how much he was enjoying watching the Olympics, and kept a record of his rides with the app @runkeeper.
Mr Harris, from Ilford, Essex and reportedly a web specialist, had only recently begun using his bike to commute into London.
On July 30, he wrote on the micro-blogging site "I'm thinking of painting my cycling helmet to make me look like Toad from Super Mario - yay or nay?"
He had only decided to take up cycling to work weeks before, after complaining about delayed tube lines.
Mr Harris had originally studied physics before becoming a social media strategist and community manager.
On his personal website, he said he enjoyed Arsenal FC, Pittsburgh Penguins, Boston Celtics, Leyton Orient, Plymouth Argyle as well as his camera and PS3.
In a statement police said: "A man aged 65 was arrested at the scene at 2128hrs on suspicion of causing death by dangerous driving and was taken to an east London police station. He has been bailed pending further inquiries to a date in late August.
"The collision is being investigated by the Metropolitan Police's Road Death Investigation Unit and enquiries continue."
Tributes flooded in for the 28-year-old after his death was announced. His friend Christopher Treloar told The Huffington Post UK: "We're all so devastated and shocked by the loss of Dan, someone who was so full of life and love. He had an incredible wealth of friends, always making time for everyone and there was never a time he didn't have us laughing at one of his jokes or many stories. He has such a loving family and girlfriend, my thoughts and prayers are with them. Everyone will miss that smile."
See below for a section of other tributes.