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Calibrate watt on Tacx trainer

Mar 10, 2009
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Hi,

How do I calibrate the watt best possible on my Tacx Bushido trainer? It shows way too low watt (No, I'm not in that bad form... :p ).

I really appriciete good answers and solutions, thank you.

Halvor :)
 
Sep 15, 2009
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I am assuming that Trainers in General are measuring Watt from a formulae based on speed, cadence etc instead of measuring actual power from a sensor ala PowerTap or SRM which is of course fine for an indoor trainer where gradient is zero and there is no wind or aerodynamic factor - but there is one variable that is not taken into account and that's the wheel/flywheel friction which is dependant on tyre pressure and flywheel tension set by the screw so in effect if you increase or decrease the pressure by turning the screw there is no adjustment made on power value. I guess you could use a PowerTap or SRM and adjust the tension so that Tacx and PowerTap (or SRM) would show exactly the same value but it will only work if you always kept the same tyre pressure and tension. Other than that the only other way would be to go by feel - basically you are better off buying a cheap basic trainer and powertap than an expensive trainer with the power features.
 
Mar 4, 2009
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Halvor:

Have you checked the Tacx user forum? Might be some information there and if not, I'd contact tech support directly. There likely is a software calibration procedure though they might have to send it to you. I ran into this issue when I reviewed an Elite Realpower trainer last year and the display was much more accurate after the calibration.

To note, though, I'm just wrapping up a test of the Bushido right now. When the tire is properly inflated, the displayed power is surprisingly accurate as compared to a reference Powertap hub.

Mondrian:

The Bushido doesn't use a standard screw-type setup for the rear roller pressure. There's a quick-release lever and the the pressure is pre-set. Any adjustments to the displayed power will have to be done in the software aside from any variance in the tire pressure.
 
Jan 23, 2010
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James Huang said:
Halvor:

There likely is a software calibration procedure though they might have to send it to you. I ran into this issue when I reviewed an Elite Realpower trainer last year and the display was much more accurate after the calibration.
.

I just ordered a Realaxiom. Do you know how accurate this virtualtrainer is ? When you said more accurate after calibration for the Realpower, how accurate is it? How you had calibrate it?

Thanks
 
Jul 15, 2009
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James Huang said:
Halvor:

Have you checked the Tacx user forum? Might be some information there and if not, I'd contact tech support directly. There likely is a software calibration procedure though they might have to send it to you. I ran into this issue when I reviewed an Elite Realpower trainer last year and the display was much more accurate after the calibration.

To note, though, I'm just wrapping up a test of the Bushido right now. When the tire is properly inflated, the displayed power is surprisingly accurate as compared to a reference Powertap hub.

Mondrian:

The Bushido doesn't use a standard screw-type setup for the rear roller pressure. There's a quick-release lever and the the pressure is pre-set. Any adjustments to the displayed power will have to be done in the software aside from any variance in the tire pressure.

Sorry to hijack the thread - will be interested in the Review. One thing i am not clear on is whtehr the Bushido is effectively a wireless Fortius. Would be interested to know if there are any differences on how the ride 'feels' in comparison. If you have an i-magic / fortius, wireless functionality alone would not be a reason to upgrade i think.