I put my 1200 Sportster up against an XR at Long Marston, Left him for dead at the start and was ahead 3/4 of the way down the track. Mine just didn't have the top end though and he just pipped me at the line. 13.1 seconds for mine and 12.9 for his. Very exciting. I could hear his carbs sucking air as he drew level with me. I think that a decent carb and filter on the standard 1200 would have made it far quicker.