Scott Hodgson, Progressive motorcycle engineer, has more than two decades of experience with motorcycle suspension. In video clip below, he walks you through a detailed setup on a Harley bagger, although the same instructions apply to those adjusting a twin-shock bike (you’ll be amazed by the difference a little tuning can make).Ride sag is the amount the suspension compresses from full extension. That includes the weight of the motorcycle rider, any passenger and equipment, such as gear packed onboard for a trip. Ride sag is the amount you’re settling into that suspension travel.An important aspect of suspension is the amount of wheel travel the motorcycle has. Wheel travel is the amount of suspension movement a bike has. For setting ride sag, Progressive recommends a rule of thumb of one-third travel as the requirement for ride sag. Since the Harley-Davidson in the video has just less than three inches of total rear wheel suspension movement, the goal would be to set a ride sag number of no more than an inch."We want to make sure at normal ride height, which is the number you achieve at the proper ride sag, you have both bump stroke – bump travel – available and you have extension travel available," Hodgson explains in the video. Extension travel comes into play from a ride comfort standpoint, and the one-third rule provides for most of the suspension travel for absorbing bumps in the road. The inch of extension travel, which is what you get when you set your ride sag, is responsible for the comfort going over speed bumps. Both are important.The video takes you through two simple measurements, first with the suspension fully extended, then with the weight the motorcycle is going to be when ridden. To find ride sag, simply subtract the second measurement from the first, the difference is your ride sag.Hodgson also takes you through the process of preloading a motorcycle for a one-up and another for a passenger or for baggage and equipment. He suggests recording those measurements in your owner’s manual so you can refer to them for quick adjustments. That way, you don’t have to measure it each and every time.If you’re in the market for Harley-Davidson suspension-related parts and accessories, visit the Progressive Suspension motorcycle parts and accessories page on JPCycles.com.