Helmet cam shows motorcyclist in shorts, thongs crash bike at 180km/h

A motorcyclist in Brazil may only have been wearing shorts and thongs when he came off his bike at speed, but at least he was wearing the helmet that captured the frightening moment.

The man's "helmet-cam" kept recording as the rider, who thankfully survived, came off his bike.

The motorcyclist can be seen overtaking a semi-trailer and passing a car before the bike begins wobbling and the rider appears to lose control.

After leaving a petrol station and taking to the highway, he gears up from 40km/h to over 185km/h as he passes the truck.

He can be seen fiddling with his helmet before the accident.

The helmet camera captures the man's legs sailing into the air before he lands and rolls over, finishing up in highway's emergency lane.

It is believed the man came through relatively unscathed - apart from some ripped skin - but it's unknown what state the motorbike ended up in.