Does the Tacx I-magic work as an ergometer like the Tacx Flow?

[151]

I am about to buy a used i-magic trainer, but have a question before I pull the trigger.

I am interested in the VR gizmos, but mostly I want to be able to program the trainer to a set wattage and pedal till the cows come home.

I used to have a Tacx basic and it is supposed to be the same as the Flow. So I am pretty sure the Flow can do this (force the rider to hold a set power output) Does anyone know if the i-magic works this way too?

Thanks

[rchung]

I am interested in the VR gizmos, but mostly I want to be able to program the trainer to a set wattage and pedal till the cows come home.

I used to have a Tacx basic and it is supposed to be the same as the Flow. So I am pretty sure the Flow can do this (force the rider to hold a set power output) Does anyone know if the i-magic works this way too?

You can set the i-Magic into ergometer mode, just as you can with the Basic and Flow. In fact, it uses the same load generator as the Basic and Flow. However, the Flow was a terrible horrendous unusable ergometer. You could set it at whatever wattage you wanted but the load generator would not hold the wattage constant. Here is a comparison of the Flow in ergometer mode with a Power Tap. If the Flow had been able to hold the load constant regardless of wheel speed, each of those groups of dots would be horizontal. They're not close to horizontal (that is, even though the wattage was set at a particular level, as wheel speed increased or decreased the load generator was unable to adjust the load properly), and the percentage error was enormous.



The Flow (and I suspect the i-Magic) were much more consistent in "trainer mode" rather than "ergometer mode" in the sense that while in trainer mode X mph always showed up as Y watts on the display head. In theory, then, one might be able to find a set of adjustments that would let you calibrate the Flow to the right power. Those settings aren't easily knowable, even with the help of a power meter. On my Flow, there was no combination of calibration number, slope, and scale that would exactly reproduce the measurements from the Power Tap. On my unit, a calibration number of +4, a slope of 3, and a scale factor of 92% would get close after the unit warmed up, though it still drifted a bit and "close" means +/- 10 watts. I've heard from others who checked their Flows against other power meters of different combinations of calibration, slope, and scale that got close so this appears to differ from unit to unit.

[151]

Thanks so much for the reply. Sounds like you are very familar with the trainer. I appreciate the info.