Bike miles versus running miles?

So I have heard 3, 4, 5, and 6 biking miles to 1 running mile. As of right now, I can't start running due to a still healing injury, however I can bike. The course I am currently using is 1.02 miles, and I just do that loop over and over. The elevation changes for this loop go as follows: from the start to .2 it is a slight downhill (1130 to 1120 ft). From .2 to .7 it is a gradual uphill (1120 to 1180ft). From .7 back to the start it is a downhill (1180 to 1130ft). Around how many biking miles on this course would be equal to 1 running mile? Also, which gear would be best (as in, should I go for more rpm, or more resistance but fewer rpm)?