Jet Black Z1 trainer Power Curve dismatches.

Jet Black Z1 trainer Power Curve dismatches.

Postby donnybike » Thu Dec 06, 2012 1:56 pm

A friend of mine has set indoor training up with Jet Black Z1 fluid trainer which is 2013 model. But he found out that the power displyed dismatches with his PRE.

At 18.6 mph, the power curve says 168 watt, but he couldn't reach to that speed. Even if he reach to that speed, he feels like exerting anaerobic power.

At 12.4 mile, he feels like riding at about tempo zone, but power displays only 70-80 watts.

Does anybody experience this with Jet Black Z1 speed-power curve?
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Re: Jet Black Z1 trainer Power Curve dismatches.

Postby David Lloyd » Sat Jul 13, 2013 8:05 am

I have found the same problem with the iBike power curve for Jetblack Z1. Luckily, I have the Dynometer version which is the same as the Z1 but with an inbuilt powermeter, so I was able to compare that side-by-side with my Newton readings. I want to use the Newton because it can record the full session along with heart rate and cadence while the Dynometer just tells you current output. What I ended up doing was taking the Dynometer power output readings and plotting them against iBike speeds readings to define a new power curve - the attached CSV file shows the difference between the Isaac power curve (column C) and what the Jetblack powermeter says (Column B). Unfortunately because I can only upload CSV you cannot see the charts or the formulae, but the co-efficients from row 22 correspond to the coefficients used in the formula in the Isaac software if you want to plot it out.

The shape is surprising because the rate of resistance flattens a bit above 340 watts where with a fluid trainer you would expect it to get steeper. But I will spend most of my time at 300 watts where it seems OK. Anyway, while the power curve given in Isaac may be bollocks, I am glad they let you edit it (or effectively create a totally new power curve).

While I have never been able to calibrate the Dynometer independently, I also go to an indoor training centre (Turbo Studio in Sydney) and the level of perceived exertion with power recorded there (calibrated Computrainer units) seems to fit with the Dynometer readings - I am in no doubt that they are much closer to the mark than the power curve given by Isaac. I am planning on comparing heart rates recorded at Turbo Studio and the Netwon/Jetblack files to fine tune.
cheers
David
Fluid Trainer Power Curve.csv
(359 Bytes) Downloaded 309 times
David Lloyd
 
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Re: Jet Black Z1 trainer Power Curve dismatches.

Postby Velocomp » Sat Jul 13, 2013 8:47 am

David Lloyd wrote:I have found the same problem with the iBike power curve for Jetblack Z1. Luckily, I have the Dynometer version which is the same as the Z1 but with an inbuilt powermeter, so I was able to compare that side-by-side with my Newton readings. I want to use the Newton because it can record the full session along with heart rate and cadence while the Dynometer just tells you current output. What I ended up doing was taking the Dynometer power output readings and plotting them against iBike speeds readings to define a new power curve - the attached CSV file shows the difference between the Isaac power curve (column C) and what the Jetblack powermeter says (Column B). Unfortunately because I can only upload CSV you cannot see the charts or the formulae, but the co-efficients from row 22 correspond to the coefficients used in the formula in the Isaac software if you want to plot it out.

The shape is surprising because the rate of resistance flattens a bit above 340 watts where with a fluid trainer you would expect it to get steeper. But I will spend most of my time at 300 watts where it seems OK. Anyway, while the power curve given in Isaac may be bollocks, I am glad they let you edit it (or effectively create a totally new power curve).

While I have never been able to calibrate the Dynometer independently, I also go to an indoor training centre (Turbo Studio in Sydney) and the level of perceived exertion with power recorded there (calibrated Computrainer units) seems to fit with the Dynometer readings - I am in no doubt that they are much closer to the mark than the power curve given by Isaac. I am planning on comparing heart rates recorded at Turbo Studio and the Netwon/Jetblack files to fine tune.
cheers
David
Fluid Trainer Power Curve.csv


When you have your curve, please email it to us and we will update our trainer list.
John Hamann
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Re: Jet Black Z1 trainer Power Curve dismatches.

Postby David Lloyd » Sat Jul 13, 2013 9:31 pm

HI John, Excel file sent.
David
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Re: Jet Black Z1 trainer Power Curve dismatches.

Postby Velocomp » Sun Aug 04, 2013 9:05 am

David Lloyd wrote:HI John, Excel file sent.
David


Where was the file sent?
John Hamann
Velocomp
Velocomp CEO
 
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