For years one had to search to find a mountain bike with flat bars, or aftermarket bars, with a sweep greater than 5 or 6 degrees. Looking at the sweep on off road motorcycles, beginning decades before mountain bikes appeared and right up to the present, handle bars with less than 5 or 6 degrees of sweep are rare indeed. The wrist position on straight, flat, bars looks and feels unnatural. I prefer something over 11 degrees.