Water bike
The water bike is a piece of sports equipment with which aquacycling is carried out.
description
The water bike can be adjusted to the height of the participant. In order to find the optimal ergonomic seating position, the bike must be horizontally and vertically adjustable on the saddle and handlebars. In order to be able to change these angles in the case of knee and hip restrictions, a medically tested ergometer usually offers the option of setting different radii on the pedal crank. This changes the flex and / or extension of the joints as indicated by the participant as a standard application for therapeutically used ergometers in rehabilitation. In addition, technically mature bikes offer the possibility of adjusting different body sizes to existing water depths using adjustable foot parts.
application
The water depth is a crucial factor for success. If the participant sits too flat in the water, a round step is no longer possible, because the thigh protrudes out of the water in the round movement in the top position and the resistance is interrupted. If the participant sits too deeply immersed in the water, he has so much buoyancy that the weight can no longer stay on the saddle and a round and harmonious pedaling movement becomes impossible.
Braking systems
Different braking systems exist in Europe to adjust the resistance. All known systems work mechanically, since the electronic brakes on land ergometers cannot be used in water. In addition to the braking systems, the moving body parts of the participants have a decisive influence on the performance to be achieved.
The following braking systems are in use:
- Water brake
Here the area as well as the C w -value of the resistance body, the angular speed with which the braking surface is rotated around the shaft and the lever arm are used.
Due to the 800 times higher density of water compared to air, the water brake system offers a special condition. The resistance increases eightfold when the cadence is doubled, cf. Air: Here, the resistance is squared when doubling.
- Frictional brake
Here a brake body is pressed onto a rotating shaft with an adjustable force. Depending on the contact pressure on the shaft, the frictional resistance and thus the performance to be provided for the participant increases. In isolation, this type of brake is independent of speed - that is, the cadence has no significance for the resistance.
Since the participant always has to move the lower extremities as resistance, this brake cannot be adjusted reproducibly and can therefore be used to a limited extent in the area of general water fitness.
- Without breaks
Here only the moving lower extremities act as brakes in the water. These are area and surface dependent. As with frictional brakes, the principle here is that the resistance is not reproducible and therefore training cannot be carried out in a targeted manner.