Years ago I read about just this thing in a book Bicycling Science(link below). It was super clever. The rear brake was on a spring loaded mount. When it clamp

Years ago I read about just this thing in a book Bicycling Science(link below). It was super clever. The rear brake was on a spring loaded mount. When it clamped down the caliper would travel a small distance to the rear before hitting a stop. It is pulled by the wheel it is grabbing. Attached to that traveling caliper is a cable to the front brake so the motion of the rear caliper would activate the front one. Neat trick effect of all this is it is near impossible to flip over the handle bars. As soon as the rear wheel leaves the ground the spring return on the rear brake pulls the rear brake forward releasing the front braking pressure. The effect is you can potential get max front braking power automatically using a simple purely mechanical system. https://books.google.ca/books/about/Bicycling_Science.html?id=0JJo6DlF9iMC&printsec=frontcover&source=kp_read_button&redir_esc=y https://books.google.ca/books/about/Bicycling_Science.html?i...