THERE are a few rules when it comes to riding a motorbike or scooter.

One is to always watch out for other motorists.

The second is to expect the unexpected.

The third would be to take extra care in the wet.

And a fourth (which should not even need to be a rule) would be to ensure your helmet is firmly fastened.

By the look of this video, the rider failed on multiple counts.

The video, shows a rider weaving in on the inside lane who is forced to brake heavily as another car weaves in front,  crossing lanes.

The rider, who is wearing a decent set of leathers, is not seriously hurt.

But as she gets up, the helmet falls off.

As one commented on Dashcam Owners Australia's Facebook page: "I've ridden a bike daily for the past 6 years and that move was fairly stupid... (especially in the wet), and how the hell did her helmet come off that easily?!"

But another said the car's driver should have indicated for longer before changing lanes.

But added, the bike rider trying to weave too eagerly into a car's blind spot is always a 'bad idea'.

"Who's going to be worse off.''

Kano Hollamby was more upset that the rider was being called a bike rider.

"This is a moron on a scooter, it is NOT a biker."

Glen Ashcroft wrote: "Both BMW and scooter both made a stupid lane change without warning.

"However the scooter was also following too closely, so hopefully learnt a painful lesson."