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Kinetic profiles

PostPosted: Thu Mar 21, 2013 1:42 pm
by dgr
Hi

I'm slightly confused over which profile to select for my Kinetic trainer. What is the difference between the Kinetic standard fluid and the Kinetic Road Machine?

Thanks,
David

Re: Kinetic profiles

PostPosted: Thu Mar 21, 2013 3:00 pm
by Bobones
This table would suggest that the power curves are identical so same trainer, different name?

http://www.kurtkinetic.com/calibration_chart.php

Re: Kinetic profiles

PostPosted: Fri Mar 22, 2013 12:25 am
by Adam
Thanks Bobones, you are exactly right. That is the source for those power curves.

Re: Kinetic profiles

PostPosted: Fri Mar 22, 2013 10:30 am
by dgr
Thanks for that.

The Kinetic website appears to be down at the moment so I can't check the formula but I know there are 2 versions of the Kinetic Road Machine power curve formula around. The correct and more accurate one is, apparently, P=S^3*0.019168+S*5.24482, the incorrect one is P=S^3*0.01968+S*5.24482. Which formula does the Kinetic Road Machine profile in PeriPedal use?

Thanks,
David

Re: Kinetic profiles

PostPosted: Fri Mar 22, 2013 8:55 pm
by Bobones
I see what you mean. Adam will need to answer that one. However at 20 mph the difference is 4 watts or 1.5% which is probably insignificant given other factors such as tyre pressure, clamp pressure, ambient temperature etc. I am sure Adam will correct the formula if Peripedal is indeed using the wrong one.

Re: Kinetic profiles

PostPosted: Sun Mar 24, 2013 1:15 am
by Adam
Hi dgr,

What is your source for the equation that you mention is more accurate?

Re: Kinetic profiles

PostPosted: Sun Mar 24, 2013 12:38 pm
by Bobones
http://www.kurtkinetic.com/powercurve.php uses the equation with 0.019168. There is also a discussion at http://blog.trainerroad.com/kurt-kineti ... tualpower/ where this is confirmed to be the correct equation.

Re: Kinetic profiles

PostPosted: Sun Mar 24, 2013 6:46 pm
by Adam
Thanks for the extra information. I've updated PeriPedal to use the more accurate equation with 0.019168. It will be part of the next update. As Bobones mentioned the difference is minor, so I won't do a special update just for this change.

Thanks Again,
Adam

Re: Kinetic profiles

PostPosted: Mon Mar 25, 2013 3:42 pm
by dgr
Hi

Thanks for that. I hadn't done the calculation and as you say Bobones, 4 watts at 20 mph isn't great. It is comforting that issues are addressed so quickly, though.

I'm fairly late to the PeriPedal beta program having used TrainerRoad for 6 months or so. I have used it for a couple of sessions now and I'm sufficiently impressed to buy a full licence. I prefer it in many ways to TrainerRoad but the big selling point is the one-off payment, which is only 4 months worth of TrainerRoad use, at present.

David

Re: Kinetic profiles

PostPosted: Mon Mar 25, 2013 9:58 pm
by Adam
Hi David,

Thank you for sharing your experience with PeriPedal, it is always fun to read a note from a satisfied user. I encourage you to share your experience with others to help expand the PeriPedal community.

Thanks Again,
Adam