American Tyler Farrar was among six Tour riders who crashed approaching the Corkscrew climb near the end of Thursday’s third stage.
The fan, identified as Anthony Tooman, loaned Farrar his bike and cycling shoes so he could finish the stage.
It is 14 years since a fan on the side of the road also loaned Australian star Michael Rogers his bike during a stage.
Roger had collided with an official’s motorbike and the moment proved crucial as he went on to win the Tour.
This time, Farrar was near the back of the race after the crash and his team Dimension Data and neutral race officials had gone ahead.
He was able to keep riding after the crash, but soon realised his gears were damaged.
So Tooman loaned Farrar his bike and cycling shoes, allowing him to finish.
Race officials could have disqualified Farrar for outside assistance, but decided not to take any action.
Cyclist Tyler Farrar Borrows Fan's Bike and Shoes to Finish Race: https://t.co/gwgMTzTuUP #TourDownUnder pic.twitter.com/30pMatFQfN
— Next Impulse Sports (@NextImpulse) January 21, 2016
“A bad crash with several other riders involved created a hectic situation which meant neither his team car nor the event’s neutral service vehicle was in a position to provide assistance,” the Tour said in a statement.
“This ruling respects the spirit of the sport and considers the rather exceptional circumstances in which this occurred.”
The race continues on Friday with the 138km fourth stage from suburban Norwood to Victor Harbor, south of Adelaide.
Orica-GreenEDGE star Simon Gerrans took the race lead by winning stage three.
Rain and even possibly a storm is forecast for Friday after three days of hot conditions on the Tour.
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