jroth

Has anyone tried using their KK power computer on a cycleops trainer?

How do you re-program the computer? I don't see any instructions in the owner's manual.

thanks.

joel

Jynx

i do not believe it can be recalibrated. all it does it take the speed read and convert it to watts. it does not actually calculate watts and doesnt show accelerations properly.

khatfull

At least the old one could, there is the following reference on the website:

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

Trainer Model A B Corresponding Formula
BlackBurn Fluid 9005 1000 9.00528x + 0.00999636x3
CycleOps Fluid 2 0747 4669 0.74715x + 0.0466912x3
Elite Fluid Alu 7113 0886 7.11346x + 0.00885877x3
Elite Volare 4660 1316 4.65979x + 0.0131627x3
Kinetic AC Pro 5245 1917 5.244820x + 0.01968x3
Kinetic Cyclone 6481 2011 6.48109x + 0.020106x3
Kinetic Standard Fluid 5245 1917 5.244820x + 0.01968x3
Kinetic Road Machine 5245 1917 5.244820x + 0.01968x3
PerformanceTravelTrac Century Fluid 4145 1217 4.145000x + 0.01217x3
Spinervals Super Fluid 4.5 5245 1917 5.244820x + 0.01968x3

I looked in the manual for the current models, doesn't seem to be that A/B setting.

I was going to pick up one of the older models on eBay just to have "watts" displayed, then pull it for non-trainer use.

Call Kurt, they'll tell you.

silversx80

Holy cripes, that equation can't be right!

If it's results are in Watts, I should go pro.

SalsaPodio

Follow his link. The first two numbers are the "A" and "B" values.

khatfull

Yeah, I just dropped that table in unformatted to show what trainers it was possible to use, at least with the old model:

silversx80

Right, I was referring to 0.74715x + 0.0466912x^3

If that's the case, than my trainer session on Wed evening left me with 105 minutes @ 295 Watts, which came after 3 harder days and was intended to be an easier effort.



Edit: I know I'm a strong rider, but there is no way I'm that strong.

Jynx

copy this into google if you want:

(0.74715(x)) + (0.0466912(x^3))

and just change the x to your speed. 20mph is about 388 watts.

silversx80

Yeah, that's what I did. 388 @ 20mph seems really high, and I know the new fluid 2's have a lighter curve than the old (I have the old), but still...



I averaged 18.2 mph after a 10 min warm up on Wednesday night for 1:45.

https://connect.garmin.com/activity/21842960

merlinextraligh

That sound pretty close to what I recall observing. Just for the heck of it, I did a chart for my Cycleops Fluid 2 when I got my PT. Don't know where I put the chart now though.

Jynx

yea i dont know why the formula is giving such high numbers. Compared to a KK it is much higher.

silversx80

If that's the case, I'm a freaking monster...


... Jeez, why did I have to spend so much on an engagement ring to where I blew all my powermeter monies?

merlinextraligh

Actually went back and dug up the file. 20mph is around 290 watts, and 18 is about 230.

Of course precise results would vary by your particular unit, and thes etup, (i.e. how tight the unit is cranked to the wheel)

If anyone is interested I can email the file.

umd

Whether or not 295W is impressive depends entirely on how much you weigh.

silversx80

Well that sounds much more reasonable, though I have to admit that I wish KK was right

silversx80

Are you saying I'm fat?

silversx80

Well, here is something interesting... I found the old power curve for the previous Fluid2's w/ the knob to tighten (the new ones have a heavier flywheel and a few other changes). It's not quite as high as what KK says, but it's not too far off. Perhaps they just picked a point on this curve and formed an x^3 tread line equation. It seems, however, the fluid2 is only a squared equation and not a cubed, like the KK.

BoodBianchi

How much would one have to weigh for that number to be impressive?

silversx80

It would really depend on the time someone is able to maintain that number in order to determine the weight. For the type of ride I did, and my weight (80 kg), it's not too shabby, especially considering that with KK's equation my FTP would be around 480-500 Watts.

umd

As long as you realize how unlikely that is...

BoodBianchi

I weigh 140 pounds, how long on my KK would I have to ride for at 20mph to be impressive? Just curious because I just started riding.

Cam

umd

Don't look to me as the artiber of what is impressive. My only point was that power by itself is fairly meaningless as weight/size matters as well. Someone who is larger/weighs more is going to require more power to go the same speed. Some people post some very "impressive" power numbers but you have to realize that they are very large as well. Someone who is tiny might actually be faster on much lower power. That is why we generally discuss power as Watts/Kg. However it should be noted that on flat ground it's actually Watts/CdA (coefficient of aerodynamic drag) that matters, it's just that it scales roughly with weight.

Edit: I'm about 65kg. All things being equal, 295W would be "more impressive" for me than silversx80 at 80kg.

And don't get me started about speed on a trainer

Jynx

20 mph = ((5.244820)(20)) + ((0.01968)(20^3)) = 262 watts.

Look at this chart for watts per kg for specific abilities

https://www.cyclingpeakssoftware.com/...profile_v4.gif

This is the formula for power on a KK Road machine where x is speed in mph.

((5.244820)(x)) + ((0.01968)(x^3))

Here is the chart made from the formula above for the power levels of a KK Road Machine Trainer. I have a powertap and my power is always within 5 watts of the chart.

https://www.kurtkinetic.com/documents..._Curves419.pdf

Take your weight and convert to kg. find a w/kg at a level you think you might be in the FTP column. find the watts and corresponding speed to get those watts. get on the trainer and see if you can hold it for an hour. if you dont have an hour do it for 20 minutes but your ftp will be 95% of the 20 minute power.

merlinextraligh

Case in point, my FTP by my last field test was 331. As for the weight side, lets just say its well north of 80kg

silversx80

About as likely as winning the lottery...

... though I did win a car once.