A former courier locked up for knocking over and killing a mother-of-two while riding an illegal Olympic-style racing bike for the “thrill” was an accident waiting to happen, a sentencing judge has said.

Charlie Alliston, then 18, was travelling at 18mph on a fixed-wheel track bike with no front brakes before he crashed into 44-year-old Kim Briggs as she crossed Old Street in east London in February last year.

Alliston was cleared of manslaughter by jurors at the Old Bailey but found guilty of causing bodily harm by “wanton and furious driving”.

Kim BriggsKim Briggs, 44, was killed as she crossed a road in Old Street in east London (family handout/PA)

The former apprentice barber raised his eyebrows as he was handed an 18-month custodial term at a young offender institution on Monday.

Sentencing at the same court, Judge Wendy Joseph QC said: “I am satisfied in some part it was this so-called thrill that motivated you to ride without a front brake shouting and swearing at pedestrians to get out of the way.

“I’ve heard your evidence and I have no doubt that even now you remain obstinately sure of yourself and your own abilities. I have no doubt you are wrong in this. You were an accident waiting to happen. The victim could have been any pedestrian. It was, in fact, Mrs Kim Briggs.”

Karan AllistonKaran Alliston. whose son will serve 18 months in a Young Offender Institution (Jonathan Brady/PA)

The judge said Alliston’s “whole manner of driving” caused the accident.

“If your bicycle had a front wheel brake you could have stopped but on this illegal bike you could not and on your evidence, by this stage, you were not even trying to slow or stop,” she said.

“You expected her to get out of the way.”

In a statement outside court, widower Mr Briggs, from Lewisham in south London, said the case “clearly and evidently demonstrated” there was a gap in the law when it comes to dealing with death or serious injury by dangerous cycling.

He said: “To have to rely on either manslaughter at one end, or a Victorian law that doesn’t even mention causing death at the other end, tells us there is a gap.

“The fact that what happened to Kim is rare is not a reason to be no remedy.”

The judge described how Alliston had repeatedly shown a callous disregard to other road users.

In a series of posts on social media following the collision, Alliston described how he twice warned Mrs Briggs to “get the f*** outta my way”.

He wrote: “We collided pretty hard, our heads hit together, hers went into the floor and ricocheted into mine.”

He complained: “It’s not my fault people either think they are invincible or have zero respect for cyclists.”

But in mitigation, his lawyer Mark Wyeth QC told the court: “What we do not have is a callous young man who doesn’t give a damn about anything.”

He said his client had suffered tragedy at the age of 16 when his father collapsed and died from a heart attack on the bathroom floor just a week before Alliston was to sit his GCSEs.

Referring to a pre-sentence report, Mr Wyeth said: “There was a lot of vilification in the case in the manner he expressed himself in posts.

“There is within him, I respectfully submit, a lot of internal sense of emotional turmoil but keeps this hidden as a coping strategy.”

The court heard Alliston was depressed, had broken up with his girlfriend and lost his job.

Prosecutors took the unprecedented step of bringing a manslaughter charge due to the unusually grave circumstances of the case.

Matt BriggsWidower Matt Briggs says the law is ill equipped to handle cases involving death by reckless cycling (Jonathan Brady/PA)

The other offence of wanton and furious driving, under the 1861 Offences Against the Person Act, carries a maximum sentence of two years in jail.

Alliston, now 20, from Bermondsey, south London, had denied both charges against him.

Speaking outside the court, Alliston’s mother, Karan, said her son had been sentenced “appropriately”.

Mr Wyeth, addressing the media in a “personal” capacity following his client’s sentence, added: “I respectfully agree with and support Mr Briggs in his dignified quest for that reform, which he undertakes in the memory of his wife.”