Police ejected bikies from several bars in Mandurah yesterday as about 100 Gypsy Jokers from across Australia and overseas set out on their annual national run.

The bikies were thrown out for wearing their colours - a practice banned under WA liquor licensing laws.

The ejections were the only report of trouble at the start of the long-weekend run which took a strange turn late yesterday when the bikies headed back to Perth from Mandurah.

A large pack of bikies set out from the gang's Maddington clubhouse on Lower Park Road about 10.30am. Dozens of police, including officers from the gang crime squad, shadowed them as they headed south on Kwinana Freeway.

A splinter group remained with the club's supply truck as it was driven through the recently fire ravaged suburb of Karnup.

Most of the pack regrouped at a service station on Mandurah Road, north of Paganoni Road, but the gang split again when they entered Mandurah town site.

There was a big police presence outside the Gypsy Joker headquarters last night with about five police vehicles, including a van, parked outside. Every driver who went past was breath tested.

The run marks the start of a year when bikies are expected to feature in headlines as feuds between new and established clubs simmer and high-profile Fink Troy Mercanti prepares for his release from jail.

In recent months, tensions between the Coffin Cheaters and the Finks have escalated and reached a head with a brawl at a public motorbike drag racing event at Kwinana Motorplex on October 3.

That fight left three Finks with severe injuries - Stephen Wallace had three fingers severed, David Marrapodi was shot in the leg and Troy Smith was bashed.

Tensions between the gangs are believed to centre on Mercanti's role in establishing the Finks in WA after he was booted out of the Coffin Cheaters. Mercanti is in jail over a brutal assault at a Northbridge nightclub.

His earliest release is expected to be mid-year after he was jailed for an extra four months for refusing to answer questions to the Australian Crime Commission, which was investigating unexplained wealth in the Mercanti family.

Members of the Rebels and Rock Machine gangs have also been feuding in recent months.

At the height of the feud, Rock Machine members were suspected of firebombing a Bibra Lake tattoo parlour owned by a senior Rebel.