Ali Mohana, 22, died after his motorbike and a car crashed in Arncliffe about 9pm.

He was rushed to hospital where he died. The male driver of the car was taken for mandatory testing and was uninjured.

Family and friends of Mr Mohana gathered outside hospital and his hairdressing shop. His sister, Layla, said he "worked so hard" to open the business at the start of the year.

"He was successful, hard-working and loved," Ms Mohana said.

"He was not only a brother but a friend, a rock for many in need of help. He was funny, always making people laugh, in times of need he was there for all, he never judged anyone, he lived life to its fullest.

"He will be missed and never be forgotten."

He was the fourth motorcyclist to die in crashes on NSW roads since Friday, prompting police to call for riders to be more careful.

About 2.45pm on Sunday, a 25-year-old man crashed into a dividing barrier on Richmond Road in Marsden Park and died at the scene.

On the same road on Saturday, a 48-year-old rider struck a tree and died.

And about 3.30pm on Friday, a 55-year-old motorcyclist died after he was thrown from his bike in the New England area.

He was riding along Guyra Road near Tingha, when his bike failed to negotiate a turn and crashed into trees. He also died at the scene.

Reports on each death will be prepared for the coroner.

Assistant Commissioner Michael Corboy from Traffic and Highway Patrol Command, said motorcyclists needed to take more care.

"It needs to serve as a stark reminder of the dangers on our roads," he said.

"We have already seen 58 motorcyclists die on our roads this year. That is 58 people who have left to go on a ride, never to return home."

He said motorcyclists needed to take responsibility for their riding behaviour.

"I want motorcycle riders to remember that they are among the most vulnerable on our roads," he said.

"Motorcycles don't have airbags or seatbelts and, when they are involved in a crash, it is easy for a rider to be seriously injured or even killed."