The 33-year-old was riding a Ducati Panagle Sports motorbike on Campsie Road on Tuesday evening when he crashed.
The incident occurred on the A891 Campsie Road between Lennoxtown and Milton of Campsie at around 8.50pm.
Emergency crews raced to the scene and the man was rushed to Queen Elizabeth University Hospital.
Cops say he is in a ‘critical but stable’ condition, but when the Glasgow Times approached Police Scotland for further information on his condition, the force was unable to comment.
The road was closed for around six hours while officers carried out investigations, and they are now urging any witnesses to get in touch.
Sergeant Jack Swindells said: “Our enquiries are continuing to establish the full circumstances of this crash.
“I would urge anyone who may have seen the vehicle involved prior to the incident, or who has any dash-cam footage, to come forward.
“In addition, anyone who may have been driving in the area around this time is asked to contact police.”
Anyone with information should call 101, quoting reference 3816 of August 1, 2023.