CYCLIST'S TARGET: Caroline Courtney was bashed in a ‘‘road rage’’ incident in Christchurch and now suffers from headaches, hearing issues and eyesight problems. She is disgusted her assailant received only four months home detention for his crime.

A woman who was bashed with a bike D-lock by a cyclist is angry at the "slap on the wrist" sentence handed down to her attacker.

Caroline Courtney, 50, fought back tears yesterday as she recalled the attack, during which she thought she was going to die.

Courtney left Christchurch to start a new life in the Bay of Plenty after the incident on December 27 last year.

She said she still suffered from headaches, and impaired hearing and vision from the attack but felt she was moving on. But she was angry her attacker was sentenced to four months home detention and ordered to pay reparation totalling $4300.

Grant David Carter-Brown, 28, was sentenced in Christchurch District Court on Tuesday after pleading guilty to charges of assault with a weapon and wilful damage.

Judge Gary MacAskill also ordered Carter-Brown to undertake psychiatric and psychological assessments.

Carter-Brown will serve the home detention at his parents' Upper Riccarton home.

Courtney said the sentence was "an absolute joke".

She had been unable to work for three months, had to get staples in her fractured skull, had bruises all over her body and still required medical treatment.

The attack was witnessed by her elderly mother and her 9-year-old niece, who still had nightmares about the attack.

"He could have killed me.

"How much is a life worth?" Courtney said.

She had not returned to Christchurch for the sentencing because she did not want to be in the same room as Carter-Brown and "trusted the system to get it right".

Had she known the sentence would be that light, she would have found the strength.

"The first judge said he would get three years [prison] as a starting point or go to Hillmorton Hospital. I would have been happy with that.

"He needs serious psychological help," she said.

During the attack, at 2pm in Sparks Rd, Hoon Hay, Carter-Brown hit Courtney repeatedly over the head with the D-lock, made of plastic-covered steel, and smashed her car's windows. Courtney said he had a "smirk" on his face the whole time.

"He knew what he was doing. I was screaming at him to stop but he wouldn't stop," she said.

Carter-Brown was grabbed by members of public as he fled the scene.

At sentencing, Carter-Brown's defence counsel, Clare Yardley, cited his mother's concerns that he might have an autistic condition arising from head injuries.

He had been injured in two or three accidents on a skateboard and a motorcycle.

Carter-Brown said Courtney's car drifted into the cycle lane and he felt threatened by her.

Courtney said yesterday she never passed him and he "came out of nowhere".

Carter-Brown is a student at the Christchurch Polytechnic Institute of Technology.

His mother declined to comment other than to say the family were "victims in this too".