Wet weather causes CHAOS in Paris Olympics time trials as cyclists struggle to stay on their bikes... with American rider falling off FOUR times and their mechanic also taking a tumble

A flurry of cyclists have fallen off their bikes on the first morning of the Paris Olympics as participants struggled to cope with the wet conditions.

US athlete Taylor Knibb skidded off four times during the women's road cycling time trials as the rain cascaded down in the French capital.

And she was soon followed by her mechanic who went flying onto the road as he rushed to give the rider a new bike.

Pre-race favourite Chloe Dygert also took a tumble on the circuit as she tried to catch up with Australian Grace Brown, who picked up gold. 

And she eventually fell short of Team GB's Anna Henderson by just one second, meaning that the British rider secured a spectacular silver medal.

The race was littered with crashes as cyclists contended with the treacherous Paris conditions, knowing that one crash would likely spell the end of a shot at a medal.

Early on, Denmark's Cecilie Uttrup Ludwig slipped on her left side before gingerly getting back on her bike.

Then disaster struck for American hopeful Knibb as the contender, who had been fastest at the 13.1km intermediate split point, fell off twice in a matter of minutes, including once in the exact same spot as her Danish counterpart.

Knibb's hopes were then completely derailed when she suffered a puncture as the rain lashed down before her mechanic slipped over himself as he arrived to replace the bike.

Even once the rain calmed down, Paris's roads remained completely waterlogged with the grey clouds and grim weather providing a dramatic backdrop for the event.

Reigning road race world champion Lotte Kopecky was the next hopeful to fall victim to the skiddy surfaces and tumbled hard onto the hard surface.

As the first riders began crossing the finish line, it was clear how the weather had taken its toll with exhausted cyclists completing the race with bloodied knees and bruised bodies.

Australia's Grace Brown nabbed a glorious gold on a chaotic afternoon to round off a career which will come to an end at the conclusion of the season.

Her margin of victory was a whopping 91 seconds - made all the more impressive by the strength of the field and testing conditions.

Behind her was Britain's Henderson who completed a gritty comeback from two collar bone injuries in the last six months.

The 25-year-old was cheered on by Olympics legend Dame Kelly Holmes who kept dry underneath a black umbrella.