Mounting locations: These bags are designed to fit inside the main triangle of your frame

The bearing cup outer diameter (OD) and the frame's BB shell inner diameter (ID) measure 46mm

Small: 140x55x55mm

Fit the Niteriders rail to allow it to fit Gobig and Combo mounts

Capacity: 320L

Cane Creek AER II Series Headset Bearing - Blue - Steel-Aluminium - 1.5 Inch - 40x52x6.5mm - 36x45 -IS52 PDP|Colour Mounting locations: These bags areGenuine Cane Creek AER II Bearing. Made from Steel and Aluminium for the lightest possible bearing. Even though it manages to shave a whopping 35% off the weight of a standard bearing, it still maintains the quality and durability that Cane Creek bearings have become known for. The best part is, these are cross compatible between all of Cane Creek's other headsets! So you can upgrade your Ten, Forty or 110 series headset to have AER II bearings.