HRD build, 13/42 stock OEM sprockets, 21" SS1 tire. I dune most of the time in 3rd. Use 4th and 5th in the higher speed areas. With the HPR#19 I can pull 4th up Olds and China Wall. Oh ya, stock swing arm. SS2 tires were too aggressive with the stock swinger. Haulers would have me on my back in the sand