David Armitage set up the event on Facebook and claims to have raised around £400 for the family of a murdered teenager, the court was told.
Armitage and 12 others are due to be sentenced for causing a public nuisance after the incident on October 31, which saw riders on motorbikes and quad bikes travel through the streets of the city, causing “mayhem” by disrupting traffic and riding through pedestrianised areas.
Andrew Horton, prosecuting, told the court: “On the 31 October last year, from approximately 5.15pm onwards, police received a number of reports from alarmed and concerned members of the public relating to a large group of motorcyclists travelling around areas of Leeds.
“The motorcyclists were travelling en masse with over 100 riders, some not wearing helmets but wearing Halloween-type face masks of varying descriptions.”
Leeds thunderstorms warning as Met Office shares latest weather forecast
Bloody machete attack on busy Leeds street left man scarred for life
York Road incident: Police appeal after pedestrian killed in crash outside Leeds Dogs Trust
Leeds Bradford Airport: Full statement on August security staff strike
Jesus Moreno: Friends looking for missing Piglove Brewing Co founder issue map of key search routes
Mr Horton said the event was advertised on private Facebook groups, with similar events taking place in Birmingham and London.
Organiser Armitage initially said the event would raise funds for Children in Need, but later said any money raised would go to the family of 17-year-old Sophie Smith, who was murdered by her 18-year-old partner.
Mr Horton said Miss Smith’s family had received no money. Deborah Smithies, defending Armitage, said the event had raised £412, but the defendant “became confused about what the appropriate thing to do with those funds was” after his arrest.
Ms Smithies said: “He has those funds and stands ready to direct them where appropriate.
“Unsurprisingly, (Miss Smith’s family) did not associate themselves with the events of that night.”
Armitage did not take part in the event due to injury, but filmed a live video on Facebook showing “exhilaration” at what was happening and telling viewers “carnage, that’s what we do”.
Mr Horton said: “He directed and encourage riders and received multiple phone calls relating to the incident.
“In essence, he repeatedly told callers and the camera that he wanted to see riders on Kirkstall Road.
“He was shown cheering and embracing riders.”
Mr Horton said CCTV and mobile phone footage showed the bikers, some who did not have number plates, in central Leeds and the Kirkstall Road area.
He said the vehicles were seen speeding, weaving between traffic, riding on pavements, in bus lanes and on the wrong side of the road, going through red lights and no-entry signs and performing wheelies and other stunts.
One group of riders drove through a narrow, pedestrianised shopping arcade in the city centre in a “dangerous and reckless manner”, with one quad bike colliding with a motorcycle and injuring the rider’s leg.
Mr Horton said: “The riders showed little or no regard for the safety of others.”
Police received around 160 calls from the public and took the decision to close a section of Kirkstall Road, which was eventually reopened at around 10.10pm.
Many of the riders expressed regret when interviewed by police.
Mr Horton said Nicholas Flaherty told police “he would never normally ride in that manner but it was such as buzz, it was like he was in a film”.
Dean Fawcett said in interview that he “thought it was a good idea but quickly realised it was turning into mayhem and that was not his intention”.
All 13 defendants pleaded guilty at an earlier hearing to “causing a public nuisance by participating in a large-scale procession of motorbikes and similar vehicles that rode around Leeds in a manner that interfered with the comfort, enjoyment and safety of the public”.
Ben Colley also admitted driving while disqualified and without insurance and Flaherty admitted perverting the course of justice by posting a message on Facebook warning people to get rid of their bikes during the police investigation.
The defendants are:
David Armitage, 26, of Brookfield Road, Leeds; Omar Ahmed, 24, of Stonegate View, Leeds; Ashley Benson, 26, of Whingate Road, Leeds; Michael Clough, 28, of Torre View, Leeds; Ben Colley, 26, of Butterbowl Road, Leeds; Dean Fawcett, 28, of Intake View, Leeds; Nicholas Flaherty, 30, of Prospect Street, Leeds; Rachel Taylor, 30, of Grange Park Walk, Leeds; Joshua Hawley, 23, of Mead Grove, Leeds; Dylan Lockwood, 23, of Torre Grove, Leeds; Adam Nicholson, 27, of Bellmount Close, Leeds, Anton Rojas, 26, of Skelton Avenue, Leeds, and Jamie Ayres, 26, of Lupton Avenue, Leeds.