Originally Posted by
Cynikal
It is my understanding that most NJS frames are built with forks that use a more round tube and less oval. This shape would weaken the fork for the stresses that are generated by the braking at the hub and not at the rim. Although I could be wrong.
Short Version: I don't think a drum brake would cause the same flex as a drum brake
Long Version: i was thinking the same thing, as road bikes have ovalized fork blades to help with the forces from braking. However, road bikes generally do their braking with a caliper. I'm not sure if this is completely correct, but consider looking at a wheel from the side, spinning clockwise. applying the caliper brake at the top is almost like adding a new point of rotation, and momentum will cause clockwise rotation about the brake. this has the effect of pushing the axle/hub towards the back of the bike.
because the drum brake has braking forces in the center of the rim, there shouldn't be any backwards flex, so a round blade tube would make no difference. It also works well for avoiding drilling your fork (but it's heavy as hell)
EDIT: derp, any braking force would cause flex in the blades and would benefit from an ovalized fork. slowing is like pulling back on the fork.