R
Robert Chung
Guest
Tacx has a line of relatively inexpensive ergometers, including the Grand Excel, the I-Magic, and
the Flow (which appears to be intended to replace the Basic). The load generator for all three
ergometers is exactly the same -- they differ in the capabilities of the computer head unit.
According to the Tacx manuals, accuracy of the ergometer will depend on:
1. the pressure between tire and roller
2. the line voltage
3. the rider's weight
The new Flow model includes a built-in rolldown test that helps to ensure that the tire-roller
pressure is consistent. In addition, one can "scale" the Flow's readings up or down if one has an
external way to measure wattage such as a Power Tap or SRM power meter (it has been reported that
Polar's power unit may not provide consistent readings on a trainer). However, the Flow's manual
omits any description of how to change either the scaling factor or to take into account the exact
line voltage.
The Grand Excel's manual describes how to alter the scaling factor, and that procedure works
on the Flow.
To change the scaling factor: unplug the cable to the Flow's computer head. While holding the SET
button, plug the cable back in, and continue to hold the SET button until the display clears. Press
the MODE button. The scaling factor will be shown and you can change it with the + or - keys, then
press the MODE button again. IF YOU KNOW your exact line voltage, you can enter it, too.
For more hints, see: http://www.topica.com/lists/wattage/read/message.html?mid=902722761
the Flow (which appears to be intended to replace the Basic). The load generator for all three
ergometers is exactly the same -- they differ in the capabilities of the computer head unit.
According to the Tacx manuals, accuracy of the ergometer will depend on:
1. the pressure between tire and roller
2. the line voltage
3. the rider's weight
The new Flow model includes a built-in rolldown test that helps to ensure that the tire-roller
pressure is consistent. In addition, one can "scale" the Flow's readings up or down if one has an
external way to measure wattage such as a Power Tap or SRM power meter (it has been reported that
Polar's power unit may not provide consistent readings on a trainer). However, the Flow's manual
omits any description of how to change either the scaling factor or to take into account the exact
line voltage.
The Grand Excel's manual describes how to alter the scaling factor, and that procedure works
on the Flow.
To change the scaling factor: unplug the cable to the Flow's computer head. While holding the SET
button, plug the cable back in, and continue to hold the SET button until the display clears. Press
the MODE button. The scaling factor will be shown and you can change it with the + or - keys, then
press the MODE button again. IF YOU KNOW your exact line voltage, you can enter it, too.
For more hints, see: http://www.topica.com/lists/wattage/read/message.html?mid=902722761
