Six men jailed over fatal bikie bashing

Six men have been jailed over the vicious fatal bikie bashing of Clint Starkey at a NSW Central Coast service station.

CCTV footage captured the 30-second attack on the 42-year-old who was punched, kicked and stomped on late on the night of April 5, 2017.

Mr Starkey never recovered consciousness, dying nine weeks after the attack at the Caltex outlet in Peats Ridge.

In the NSW Supreme Court on Friday, Justice Desmond Fagan jailed the four assailants as well as two brothers involved in the lead-up to the attack.

All were associated with the Rebels outlaw motorcycle gang.

Adam David Symons, 41, Beau Andrew McDonald, 30, and Guy Keith Robertson, 33, were found guilty of murder on the basis of joint criminal enterprise to assault the victim.

Jake William McDonough, 30, was found guilty of manslaughter.

Brothers Colin Steven Crane, 55, and James Peter Crane, 57, who were not present during the attack, were found guilty of murder on the basis that they were accessories before the fact.

Conflict had developed between Colin Crane, who had mental health issues, and Mr Starkey who tended to be irritable, impulsive and reckless.

"It was largely a matter of friction between incompatible personalities," the judge said.

Their mutual antagonism escalated in the days before the bashing, when Mr Starkey made various threats including to shoot up the home of Colin Crane's partner, which he repeated to her at her workplace.

"It is evident that Colin Crane was able at a moment's notice to call up physical attendance of Rebels members to act at his behest in conflict," the judge said.

He found he was considerably provoked by the conduct of Mr Starkey, who had a reputation for erratic conduct and was once involved in a notorious confrontation with police involving firearms.

His brother James had passed on information that Mr Starkey was going to the Caltex station with a friend.

His contribution to bringing about the fatal assault was "minimal" being a conduct for one piece of information that enabled his brother to direct the assailants to their target.

They drove in two cars to the garage, where Mr Starkey was dragged from his friend's car and attacked.

The judge found Symons and McDonald kicked and stomped on their victim, continuing the attack after Robertson and McDonough walked away.

"Robertson's participation was the most vicious, commencing with a powerful kick to the head followed by further kicks to the head and shoulder region."

Robertson returned when Mr Starkey was motionless on the ground, delivering four powerful stomps to his head.

McDonough was the last to arrive when Mr Starkey was dragged out of the car and the first to break off from the assault.

Symons was jailed for 18 years with a non-parole period of 12 years; McDonald for 17 years and six months with a non-parole period of 11 years and six months; and Robertson for 19 years with a non-parole period of 13 years.

McDonough was sentenced to seven years and six months with a non-parole period of five years.

Colin Crane was jailed for 16 years with a non-parole period of 10 years and nine months, his brother for six years with a non-parole period of four years.

"The court has received a victim impact statement from Mr Starkey's mother and father, two decent, kindly country people in their 70s," the judge said.

"Theirs is the grief of elderly parents, seeing an adult son robbed of many years of life that should have remained to him."