The choice of nipple material inspires zealotry — some prefer brass, some prefer aluminum, others a mix of materials. Brass nipples are more popular because they’re cheaper, stronger and more corrosion resistant. Aluminum nipples feature superior finishes at one third the weight. How to choose? If you’re hard on gear, clean infrequently or ride in adverse conditions, then brass is a sensible choice. For scenarios where weight and performance matter, aluminum is the way to go.
Working with aluminum nipples shouldn’t inspire fear — in fact many find aluminum nipples turn more smoothly. How do pros work with aluminum? First, use liberal lubrication. When building in the first place, make sure threads are fully covered with oil or other spoke preparation compound. When making adjustments down the road, dribble a thin oil into the nipple and into the rim at the base of the nipple. Second, avoid stressing aluminum nipples by using a 4-sided spoke wrench (e.g. Park Tool SW-40). Compared to a regular 3-sided wrench, a better tool distributes forces more evenly. If your nipple has a secondary hex interface on the rear, that’s a safe way of applying torque too. Last buy quality aluminum nipples. For example Sapim nipples are made of 7075 aluminum, a stronger alloy that is not the industry norm. Sapim anodizes silver nipples for corrosion resistance whereas other makers ship these raw. From a quality perspective aluminum nipples are less interchangeable across brands.