Kurt Kinetic Power Computer a worthwhile training aid?

bigpikle
bigpikle Posts: 1,690
I have a Road Machine TT and will be using it extensively over the winter like many people. Right now I have no power meters or equipment, just a 705 & HRM , and I just cant afford to buy a PT or anything else right now. Also, with several bikes I just cant find a solution that would work with all of them if I rented etc...So.....

Is it worth £50 to get the Kurt power computer for use on the trainer? My goal would be more targeted training using power rather than HR, and being able to test myself to measure progress. It seems the Kurt is pretty accurate as TT power computers go, but as you cannot download any data and it only shows max, av and current power, is there enough data to make it worthwhile?

My thinking is that if I can calculate the power zones I want to target (using the Kurt) for different intervals etc then being able to train against these zones must be more helpful than using HR data alone?

Before I splash the cash would someone tell me if I am wasting my time. Please dont recommend a PT etc as its just not going to happen for a long time yet!
Your Past is Not Your Potential...

Comments

  • Don't buy the KK Power Computer. All it does is measure rear wheel speed. It then uses the known power curve of the KK Road Machine to translate this speed into a power reading.

    Assuming you have the speed sensor for your 705, then you are already able to measure your rear wheel speed. After your turbo session simply use the equation quoted on the KK website to work outy our power readings for any workout. The 705 is actually better for this as you can work out ave power for individual intervals - you can't do this on the KK power computer. Indeed, you can in effect set up power zones on the 705 using the speed zones function. Done this all year and it works great.

    None of the above is to say that this method is anywhere near as accurate/consistent as using a proper power meter. However, it is a good way of ensuring that your training intensity is roughly where it should be.
  • swaman
    swaman Posts: 110
    if you have any computer that will show speed then you don't need a kurt computer

    you can download and print out the power curve from the kurt website, it will show power against speed

    i use my garmin 705 on the bike and when I upload my speed after a session i can see where i was in relation to power

    easy to do power intervals, just look at the speed you need to do and keep it in the relative speed zones during your workout

    i also have an i-magic which does gave power and all the extras but rarely use it, the Kurt power figures are more realistic to road figures, the kurt is easier to set up, and it rides much better

    hope this info makes sense...

    if you want to have an all-fangled system with all sorts of power data and graphs etc then then you need the powertap

    but if you just want to set power targets, do power sessions on the turbo, and keep a l diary of your progress, then the kurt kinetic linked with a computer that shows speed will do a great job
  • bigpikle
    bigpikle Posts: 1,690
    thanks guys - I obviously need to get my head round this speed/power equation and plot a curve...

    So, if I use the 705 lap feature to record each interval then I can find av speed per lap/interval and hence av power per lap/interval. By the same process I can also identify the speed range that corresponds with the target power range and work to stay in that speed range...

    Seems to make sense if I can work the equation then.
    Your Past is Not Your Potential...
  • swaman
    swaman Posts: 110
    you can use the equation or use the power curve chart, you will find it here

    http://www.kurtkinetic.com/documents/Po ... ves419.pdf

    makes life a lot easier...hope this helps
  • bigpikle
    bigpikle Posts: 1,690
    thanks - I managed to reproduce it in Excel so I can print the graph etc and have it by the machine. My next job was some algebra to see if I could calculate the speeds for a particular power level? Been a while since i tried that though....
    Your Past is Not Your Potential...
  • Slow1972
    Slow1972 Posts: 362
    Bigpikle wrote:
    thanks - I managed to reproduce it in Excel so I can print the graph etc and have it by the machine. My next job was some algebra to see if I could calculate the speeds for a particular power level? Been a while since i tried that though....

    That's what I've done. I self tested to find avg speed at threshold, converted that into power. I've then used excel to calculate the corresponding speed for varying percentages of threshold power. I've then just knocked up a table which gives me the speed on the Kurt for different % of threshold from 50% through to 140% in 5% increments. I just have it taped on the wall next to the turbo. I just use a cheapish Cateye computer with rear wheel mounted speed sensor, I found the signal on my Garmin sensor seemed to keep dropping out a bit which was adversely affecting the averages I achieved.
  • bigpikle
    bigpikle Posts: 1,690
    Slow1972 wrote:
    That's what I've done. I self tested to find avg speed at threshold, converted that into power. I've then used excel to calculate the corresponding speed for varying percentages of threshold power. I've then just knocked up a table which gives me the speed on the Kurt for different % of threshold from 50% through to 140% in 5% increments. I just have it taped on the wall next to the turbo. I just use a cheapish Cateye computer with rear wheel mounted speed sensor, I found the signal on my Garmin sensor seemed to keep dropping out a bit which was adversely affecting the averages I achieved.

    can I ask what you did to find your speed at threshold? This is the last pice of the puzzle for me as I cant work out how best to find the training zones?
    Your Past is Not Your Potential...
  • Useful reads:

    http://alex-cycle.blogspot.com/2008/05/ ... -sins.html

    http://alex-cycle.blogspot.com/2009/07/ ... ftp-2.html

    In the context of the KK, just read 'speed' for 'power'. A mainstay of my training is the typical 2*20 workout. I do these sessions as hard as I can. I then use the ave power over the 2 intervals as a rough indication of my threshold power.

    As stated above, this is not the most accurate way of assessing threshold power, but for my purposes it does fine.
  • Murr X
    Murr X Posts: 258
    This is a good conversion table for the KK Roadmachine. Print it out and have it in view when on the turbo.


    MPH - WATTS

    17.0mph=183.34w
    17.1mph=185.53w
    17.2mph=187.74w
    17.3mph=189.98w
    17.4mph=192.23w
    17.5mph=194.51w
    17.6mph=196.80w
    17.7mph=199.12w
    17.8mph=201.46w
    17.9mph=203.81w

    18.0mph=206.19w
    18.1mph=208.59w
    18.2mph=211.01w
    18.3mph=213.45w
    18.4mph=215.91w
    18.5mph=218.39w
    18.6mph=220.89w
    18.7mph=223.42w
    18.8mph=225.96w
    18.9mph=228.53w

    19.0mph=231.12w
    19.1mph=233.73w
    19.2mph=236.36w
    19.3mph=239.02w
    19.4mph=241.70w
    19.5mph=244.40w
    19.6mph=247.12w
    19.7mph=249.86w
    19.8mph=252.63w
    19.9mph=255.42w

    20.0mph=258.24w
    20.1mph=261.07w
    20.2mph=263.93w
    20.3mph=266.81w
    20.4mph=269.72w
    20.5mph=272.65w
    20.6mph=275.60w
    20.7mph=278.58w
    20.8mph=281.58w
    20.9mph=284.60w

    21.0mph=287.65w
    21.1mph=290.72w
    21.2mph=293.82w
    21.3mph=296.94w
    21.4mph=300.09w
    21.5mph=303.26w
    21.6mph=306.45w
    21.7mph=309.67w
    21.8mph=312.92w
    21.9mph=316.19w

    22.0mph=319.48w
    22.1mph=322.80w
    22.2mph=326.15w
    22.3mph=329.52w
    22.4mph=332.92w
    22.5mph=336.34w
    22.6mph=339.79w
    22.7mph=343.26w
    22.8mph=346.76w
    22.9mph=350.29w

    23.0mph=353.84w
    23.1mph=357.42w
    23.2mph=361.03w
    23.3mph=364.66w
    23.4mph=368.32w
    23.5mph=372.01w
    23.6mph=375.72w
    23.7mph=379.46w
    23.8mph=383.23w
    23.9mph=387.03w

    24.0mph=390.85w
    24.1mph=394.70w
    24.2mph=398.58w
    24.3mph=402.48w
    24.4mph=406.42w
    24.5mph=410.38w
    24.6mph=414.37w
    24.7mph=418.39w
    24.8mph=422.44w
    24.9mph=426.51w

    25.0mph=430.62w
    25.1mph=434.75w
    25.2mph=438.91w
    25.3mph=443.10w
    25.4mph=447.32w
    25.5mph=451.57w
    25.6mph=455.85w
    25.7mph=460.16w
    25.8mph=464.49w
    25.9mph=468.86w
    26mph=473.26w


    With a bit of work I had got it amazingly close to my SRM Pro from 250-350 watts. Make sure that the tire pressure is always identical and the unit is tightened to the same degree (app 3 revolutions for mine, after contact with the tire) each time as this will greatly affect the accuracy and consistency.

    Also it must be warmed up, however due to the fluid used in the resistance unit above a certain temperature it is very stable and in my experience does not suffer from reduced viscosity and therefore does not overestimate power output above this temperature.

    The KK is a very good piece of kit and as just mentioned can be surprisingly accurate with a bit of effort, but it is not great if improperly set up.


    Murr X