Bicycle brake brakes are slightly heavier than conventional side-pull calipers and cannot accurately track an out-of-true rim, or a wheel that flexes from side to side in the frame during hard climbing. It is common to see professional racers climbing mountains with the quick-release undone on the rear brake, to eliminate drag from this source. This type of brake has symmetrical arms and therefore centre more effectively. The cable housing attaches to a fixed cable stop attached to the frame, and the inner cable bolts to a sliding piece (called a "braking delta", "braking triangle", or "yoke") or a small pulley, over
Lifting bag a hazardous operation with high risk of entanglement in an uncontrolled lift or sinking. If a single bag is insufficient, multiple bags may be used, and should be distributed to suit the load. There are also lifting bags used on land as short lift jacks for lifting cars or heavy loads or lifting bags which are used in machines as a type of pneumatic actuator which provides load over a large area. These lifting bags of the AS/CR type are for example used in the brake mechanism of rollercoasters. The volume of the bag determines its lifting capacity: each litre