Cyclists can start signing up from Saturday for the Hong Kong Cyclothon, which will be held on December 18 after a four-year break.

The Tourism Board, which co-organises the event, said on Thursday it will feature 3,000 cyclists on a 50-kilometre route that starts in Tsim Sha Tsui and goes through the Tsing Ma Bridge, Ting Kau Bridge, Stonecutters Bridge and several tunnels before ending in Tsim Sha Tsui.

Those who haven't taken part in the cyclothon before will have to pass a skills test to join the event, which also includes a 30-kilometre ride as well as individual and team time trials in Tsim Sha Tsui.

All participants will have to be triple-jabbed and produce a negative PCR test result two days before race day and take a rapid antigen test on the day.

Cyclists will not have to wear masks during the race.

Asked why the jab requirement is tougher than the vaccine pass system, Tourism Board chairman Pang Yiu-kai said the rules were made in compliance with government demands.

He said this will be Hong Kong's biggest outdoor sporting event since the Omicron wave, so the government wants a higher level of protection.

The event is back after a four-year hiatus, and Pang said he's hopeful it can go ahead this time round.

"According to the government, whatever measures they have done to relax the restrictions on movement or social gatherings, they will not [roll] it back," he told a press conference. "We will follow and respect the government's line, but if there's a major outbreak and if we're told to postpone the event... of course the health of the community comes first."

The Hong Kong Cyclothon will be held between 5:30am to 1:30pm on December 18. Road closures will begin from 1am, and all roads are scheduled to reopen by 4:30pm.