What are the differences between alloy and brass nipples?

Brass nipples are stronger and more corrosion resistant than alloy nipples. Alloy nipples are lighter (by approximately 35g per wheelset) and available in a variety of anodized colors. For MTB, CX and disc brake applications brass nipples are recommended for strength and durability. For most road applications, alloy nipples will suffice. Choose brass nipples for durability and strength, choose alloy nipples for bling and weight savings.