The cyclist, named as 47-year-old Keith Allen, from Garnswllt, had been cycling on the Heol Glyn Dyfal road in Felindre.
Mr Allen was found deceased on the grass verge at the side of the road on Sunday 6 August.
Detective Sergeant David Connick from South Wales Police said: “Our thoughts are with Keith’s family and friends at this time.
“Inquiries are ongoing to establish why he came off his bike, so we are keen to speak to anyone who may have been on that stretch of road between 8.30pm on Saturday 5th August and midnight on Sunday 6th August who may have information or dashcam footage that could assist our investigation.”
(Lead image: Google Maps)
