The victim, a 32-year-old man, was riding along the cycle path on Jenny Field Drive at around 11pm on Sunday 30 June 2013 when he was attacked as he passed a ginnel near Harewood Drive.
He suffered facial injuries in the incident – including a broken nose and a missing tooth – and was treated at Harrogate District Hospital.
The men who assaulted him were all wearing dark-coloured clothing.
Police are appealing to anyone with information about the assault or can help to identify those responsible, to get in touch.
Anyone who can help officers with their enquiries is urged to contact North Yorkshire Police on 101 – select option 2 – and ask for Detective Constable Fiona Ayre or Harrogate CID.
Alternatively, information can be emailed to firstname.lastname@example.org
If you wish to remain anonymous, Crimestoppers can be contacted on 0800 555 111.
Please quote reference number 12130108158 when passing information about this incident.