The Bendix brake system uses "servo" action, where the forward rotation of the wheel pushes the brake shoe assembly toward the rear of the drum. The front (primary) shoe is shorter because most of the braking action is done by the rear shoe through the servo action.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!