Police were called to a report of a serious incident in Alma Hill at around midday on Saturday (January 22).
A 60-year-old man had suffered serious head injuries and lower leg fractures after falling off his Obsydian ARX Pro bike.
The casualty, from Wigan, was airlifted to Aintree Hospital for treatment.
A spokesman for Lancashire Police said: "Police are appealing for witnesses and urging anyone with information to come forward.
"If you saw what happened and can help, please call 101 or email [email protected] quoting log 0667 of January 22."
Information can also be reported online at doitonline.lancashire.police.uk.
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