RACING at speeds of up to 80mph with no protection makes road cycling one of the most dangerous sports in the world.
Seasons can be ended in a split second by terrifying crashes, like the one witnessed at the start of this year’s Tour de France at the weekend.
The peloton pile-up was caused by a dozy fan holding up a sign in front of a rider.
But it didn't stop Julian Alaphilippe going on to pick up the Yellow Jersey that day, even though he was covered in blood.
Hospitalisations, broken limbs and serious head injuries are par for the course when riders go wheel to wheel.
Earlier today, Geraint Thomas suffered a dislocated shoulder - but, like many other bloodied sports stars, he got back on his bike and hurtled towards the finishing line in agony.
Here were look at some of the worst crashes in cycling’s history.
Chris Froome
Two years ago Britain’s four time winner of the Tour de France hit a wall at 33mph while testing out a time trial course.
Froome, 36, had lifted one hand to clear his nose and lost control.
He was ruled out of the French Grand Tour because he had broken his ribs, hip, a neck vertebra, right femur, elbow and sternum.
Luis Leon Sanchez
Spanish rider Luis Leon Sanchez needed to have his arm stapled together and suffered four broken ribs after a high speed smash.
During the 2018 Tour de France the 37-year-old rider struck a road sign.
Somehow, Sanchez completed the stage, but doctors later insisted he could no longer take part in that year's competition.
Laurent Jalabert
Top French rider Laurent Jalabert was in a pack hitting speeds of 37mph during a sprint finish in 1994 when he was caught by the long arm of the law.
The police officer was attempting to take a photograph of the riders when he got in the way of four riders.
Jalabert, 52, was the most badly injured, suffering broken teeth and fractured cheekbones. Afterwards he promised his wife to avoid sprint finishes.
Sandy Casar
Competing on national roads means that Tour de France riders face all kinds of unexpected hazards.
In 2007 Frenchman Sandy Casar, 42, was left dripping with blood after a dog wandered out into the middle of the pack.
By swerving to avoid the pooch riders ended up in a heap. But Casar got back on his bike and won the stage.
Annemiek van Vleuten
Olympic fans feared the worst when road race leader Annemiek van Vleuten lay motionless following a bone crunching accident in Rio in 2016.
Next thing I remember I was awake in a hospital bed
Annemiek van Vleuten
She lost control navigating a downhill bend and cartwheeled over the verge, landing on her shoulders.
Afterwards the 38-year-old Dutch rider said: “The corner surprised me and I didn't take it properly. Next thing I remember I was awake in a hospital bed and I had my mother on the phone."
Emanuel Buchmann & Jos van Emden
A powerful wind cutting across a lagoon caused a nasty chain reaction during this year’s Giro d’Italia.
The race had to be stopped for a quarter of an hour so that riders could receive medical treatment after smashing into each other.
Top German competitor Emanuel Buchmann, 28, was unable to continue in the Giro.
Jonny Brownlee
When another cyclist fell in front of triathlete Jonny Brownlee in the wet, the Brit crashed into barriers.
While Jonny, 31, was fit enough to continue during the race in Japan in 2017 his bike wasn’t.
So the Olympic bronze medal winner carried it for a mile.
Bernard Hinault
One of the most legendary recoveries was made by French cyclist Bernard Hinault during the 1985 Tour de France.
Less than a mile away from the end of stage 14 he broke his nose after landing on his head.
But with the chance of a fifth Tour win in the balance he got up and finished with his face bloodied.
Hinault’s perseverance was rewarded when he became champion again.
Read more from tour de france
Johnny Hoogerland & Juan Antonio Flecha
Camera crews and team support travelling in cars often come dangerously close to competitors.
In 2011 Dutchman Johnny Hoogerland, 38, and Spaniard Juan Antonio Flecha, 43, were sent flying at 37mph when a car got in the way.
Hoogerland landed on barbed wire, requiring 33 stitches and 17 minutes medical treatment.
READ MORE SUN STORIES
Both men finished the stage, but the Dutchman suffered long lasting back pain.