Originally Posted by
Dan Burkhart
The brake arm does nothing to prevent the axle from rotating. It simply anchors the brake.
Thanks, Dan. But I look at this thinking of a "free body diagram". (You may know this approach better than I do, pardon me for explaining). So I look at the axle. It's separated from the hub's torque by bearings. The hub has on one side the freewheel and sprocket(s) and is separated from the axle, with little torque transmitted, by the same bearings. The roller brake assembly has its inner part fastened to the hub on the ND side, and this part rotates (normally with no torque tranmitted to the outer part of the brake because of a bearing. The outer brakepart is attched to the inner part by a bearing, and to the frame by the brake arm and clip. No braking? No torque on the outer brake part. Braking? The inner and outer brake parts transmit torque to each other, and the inner part transmits torque to the hub, but I can't see where torque gets transmitted to the axle.
My first Scwhinn Typhoon had a similar arrangement. The brake arm handled the torque. The axle nut was just a regular nut, with a washer.
Is there something in these hubs that transmits torque to the axle?