Police are appealing for information following a collision between Lampeter and Llangybi on Monday afternoon.
Dyfed-Powys Police says officers are investigating the collision between a black Toyota pick-up truck and trailer and a blue Harley Davidson, which occurred on the A485 between Lampeter and Llangybi on Monday, 9 September, just before 3pm.
The female rider of the motorcyclist was taken to hospital with injuries not believed to be life threatening.
A 66-year-old man was arrested on suspicion of causing injury by dangerous driving. He has been released under investigation pending further police enquiries.
The road was closed for four hours.
Witnesses, or anyone with dashcam footage, is asked to report it to Dyfed-Powys Police, either online or by calling 101, quoting 211 on the 9th.