Hub Flange Interface

Wheel hubs have two flanges, one on either side, in which spokes connect to. There are several different types of interfaces used that enable spokes to be connected to a hub flange.

A "classic" hub flange generally refers to a series of holes drilled into the side of a flange in which J-hook spokes can be dropped through. These holes are orientated perpendicular to the running direction of the flange.

Another system, commonly referred to as "straight-pull" has several different interfaces so it can be difficult to discern what the subtle differences are. The hub flanges of a straight-pull hub also have a series of holes drilled into them however they run parallel with the direction of the hub flange. Within the hole there is a small shoulder for the head of a straight pull spoke to sit on so it doesn't pull through. The exact shape of this spoke head shoulder can vary from brand to brand so not all straight-pull spokes are compatible with every straight-pull hub.