Spot basis bids for hard red winter wheat were unchanged in the southern US Plains on Wednesday as farmers focused on the impending corn harvest, grain merchants said. Front-month HRW wheat futures were down 3-1/4 cents at $4.72-3/4 a bushel by 10:55 am CT (1555 GMT), hovering near last week's five-year low of $4.69-1/4. Protein premiums for railcar wheat to and through Kansas City were flat on Tuesday.