Szívóhát

Szívóhát is a Hungarian term that translates literally to "suction back" or "vacuum back." It most commonly refers to a type of bicycle brake system, specifically a caliper brake design. In this configuration, the brake caliper is mounted such that the brake pads are drawn towards the rim by the rotational force of the wheel itself, rather than being pushed by a spring or lever action.

This design was more prevalent in earlier bicycle technology. The principle behind szívóhát brakes is that as the wheel spins, the air pressure and the slight deformation of the rim can create a subtle suction effect that helps to engage the brake pads. While this can provide a degree of braking, it is generally considered less powerful and less consistent than modern brake systems, such as side-pull or dual-pivot caliper brakes, or disc brakes.

The szívóhát design often has a more rudimentary mechanism for pad retraction, and its effectiveness can be significantly influenced by environmental factors like dirt and water on the rim. Due to the limitations in braking power and modulation, szívóhát brakes are rarely found on new bicycles today, having been largely superseded by more advanced and reliable braking technologies. They are primarily of historical interest to bicycle enthusiasts and collectors.