Two motorists are tonight in serious condition after a collision between a motorcycle and a rental bike at the junction of Harbour Road and Morgan Road in Warwick.Police said the collision occurred at 5.30pm, between a 33-year-old Southampton man and a 52-year-old male contract worker.Evening traffic toward the West End was backed up as a section of Harbour Road had to be temporarily closed off for emergency services.Both men were taken by ambulance to King Edward VII Memorial Hospital for treatment.