Original sentence: All involved lightweight high-powered sports bikes, which are usually Japanese makes, and not heavier cruisers, such as Harley-Davidsons, BMWs and Indians, the department said.Despite frequent crashes, there have not been any motorcycle fatalities on the mountain in the past three years, Lucia said.He credits the protective equipment most thrill seekers wear.Popularity and difficulty of the road is such that, on a typical warm-weather weekend, an average of two motorcycle crashes requiring medical attention occur in the area.South Grade Road, the stretch of San Diego County Route S6 going from State Route 76 to the summit, is popular among sport bike riders and sports car drivers due to its challenging nature (over 20 hairpin turns over the distance of less than ) and low traffic on most weekdays, though thrill seekers prefer to visit on weekends(when traffic is busiest) much to the dismay of visitors and residents alike
Edited sentence: South Grade Road, the stretch of San Diego County Route S6 going from State Route 76 to the summit, is popular among motorcycle riders and sports car drivers due to its challenging nature  (over 20 hairpin turns over the distance of less than )