Lighter weight shafts can yield lighter swingweights. Generally speaking, 9 grams of shaft weight reduction will reduce the swingweight by 1 swing weight point. This can vary slightly depending on the balance point of the shaft. Club length is also a factor. Important to understand what swingweight really is. It is “A club’s weight distribution around a fixed fulcrum point. The fulcrum point is typically 14″ from the butt of the club. Swingweight is commonly referred to as the weight distribution of the grip, the shaft and the head through a given club length.” This comes from our glossary of terms and is commonly accepted as the definition. If you like D1 and are using a lighter weight shaft and say a standard 50 gram grip and the club lengths are men’s standard, chances are it will be lighter than D1 without some weight added. No issues adding 4-6 grams to get to the number you want. We generally do not want to see any more than 8 grams added. At the end of the day, it really does not mater what the swingweight number is, just that with whatever configuration of components and club length you use, the clubs provide you with the head feel YOU want when swinging the club.