Kurt kinetic - Bizarre Computer Readings

BullGod said:

Last night I did a 2 hr session on my new KK - involving 3 x 20 minute intervals at "80%" with 10 minute active recovery periods in between.

The readouts on the computer were really strange. during the recovery they seemed fine - 28km/h - 180w or something.

However - during my 20 minute L4 intervals the speed stayed at 33km/h with the wattage fluctuating between 335, 300, 280 and 260 almost randomly every few seconds, even though it totally felt as if my output was steady. The speed was only changing between 33,9 and 33,8 etc.

I find it really bizarre that my "20 minute" speed would be 33. I wasn't going full on but on the flat without too much wind I can do a sub 60 minute 40km TT no problem at any time of year, and I can hold the bike above 40km/h for 20 minutes without too much difficulty on a normal bike setup.

I found it also strange that I was doing about 100rpm in 53 x 17 and it was saying 33km/h. That can't be right!

I've been riding long enough to know what it feels like to ride at 30, 35, 40, 45 and 50 etc and what the KK said was 35 felt like at least 45.....I was gasping like I was off the front of a crit!

I checked the power formulas so apart from me changing from a a Cat 1 to a Cat 4 after one month of LSD ;-) the only things I can think of are:

1) dodgy computer
2) roller too tight against wheel (I did 3 turns)
3) Special trainer tyre combined with roller too tight
4) wrong wheel circumference - is now set at 2060 - isn't that what all race wheels are?

Is there some sort of "coast down" check to see if you have the roller too tight maybe?

This is concerning me, cos apart from that it is an awesome trainer, natural feel, quiet, easy to setup....

any ideas?

Yeah that does sound kinda strange, when I first bought my KK it did a few strange things. I haven't paid much attention to the number of turns. I've just checked to make the wheel don't slip off the roller. Are you sure the comp was in the right setting when you were reading it? If it happens again maybe take out the battery, put it back, and start again -thats what I did and its hasn't fluctuated like yours since. Good luck

Ade Merckx said:

Yeah that does sound kinda strange, when I first bought my KK it did a few strange things. I haven't paid much attention to the number of turns. I've just checked to make the wheel don't slip off the roller. Are you sure the comp was in the right setting when you were reading it? If it happens again maybe take out the battery, put it back, and start again -thats what I did and its hasn't fluctuated like yours since. Good luck

now that yours works better does it "hold" the wattage better? I mean, can you easily hold it at say 260, or does it jump from 300 to 210 all the time?

BullGod said:

now that yours works better does it "hold" the wattage better? I mean, can you easily hold it at say 260, or does it jump from 300 to 210 all the time?

yeah definitley. I wish I could hold it close to your FT numbers though🙂

Ade Merckx said:

yeah definitley. I wish I could hold it close to your FT numbers though🙂

I'll start over from scratch again with the battery and config tonight.

don't worry about FT numbers.....no matter what your number is it still hurts the same for everyone!

Thanks for your help.

BullGod said:

I found it also strange that I was doing about 100rpm in 53 x 17 and it was saying 33km/h. That can't be right!

33 = 84rpm. 100 is a tick under 40kph

Quoted post said:

4) wrong wheel circumference - is now set at 2060 - isn't that what all race wheels are?

Although there is slight differences depending on manufacturer, pressure or worn out tyres a 23 will be ~ 2096. I measure with a dot of paint on a loaded tyre 🙂

I've had problems with the sensor not being able to pick up the wheel magnet at times. In your case it sounds like it may be missing a revolution every so often. Usually moving the sensor closer to the magnet solves the problem. It could also be a low battery. Mine needed replacement after only 3 months.
I'll be happy when I get my PowerTap in a few weeks. The KK computer is cheesy - I've already had one go out on me.

strader said:

I've had problems with the sensor not being able to pick up the wheel magnet at times. In your case it sounds like it may be missing a revolution every so often. Usually moving the sensor closer to the magnet solves the problem. It could also be a low battery. Mine needed replacement after only 3 months.
I'll be happy when I get my PowerTap in a few weeks. The KK computer is cheesy - I've already had one go out on me.

Mine worked for about a day and even then it was inconsistent. Two of my friends sent their KK computer back to the dealer. I wish I had, but I kept trying over a period of time to get it to work right and I never could.

BullGod said:

...I find it really bizarre that my "20 minute" speed would be 33. I wasn't going full on but on the flat without too much wind I can do a sub 60 minute 40km TT no problem at any time of year, and I can hold the bike above 40km/h for 20 minutes without too much difficulty on a normal bike setup....

I can't speak for your erratic power readings, but the KK is power calibrated to assume a 165 pound rider on a 1% grade, not riding flat.

Here's a clip from KK's site:

Quoted post said:

With Tom’s(Compton from analyticcyling) help, we have been able to create an “average” rider assumed to be 165 lbs, riding a 23 lb bike with 170mm crank arms up a 1% grade, at sea level with no wind on rough asphalt... etc. The “outdoor ride” that we reference in the PDF is based on this “average” rider. Tom was then able to calculate how much power it would take for our average rider to maintain a given speed.

Anyway, it takes roughly 250 watts to hold 20 mph on a KK trainer but you'd go much faster outside on a flat road with that same power.

-Dave

Re the computer....I had some dodgy readings with mine as well. I eventually got Kurt to send me a replacement which so far seems to be giving readings that make sense.

Low readings, but then that's not Kurt's fault.

I'm looking to get a trainer with power since I can't afford a power tap.
It seems a lot of people have had problems with the KK.
I thought it was the best power turbo out there, but maybe I'm wrong.
Are there any other turbos with power that people would recommend?

Hi

There are no problems with the trainer - it works great. Just the little speed / power accessory you can buy for it, but Kurt will fix that up for you if you have a difficulty.

Yojimbo_ said:

Hi

There are no problems with the trainer - it works great. Just the little speed / power accessory you can buy for it, but Kurt will fix that up for you if you have a difficulty.

this is really dumb - but I now know what the problem is.

On friday I did a 1hr "hard ride" and got an average of 290w.....which is low for me.

When I was disassembling the trainer I noticed that my wheel was not in perfectly and the tyre was rubbing against the frame. I then adjusted ther wheel position and noticed a much more steady and predictable power output that was nearer to 350 than 250.....

whoops ;-)

BullGod said:

this is really dumb - but I now know what the problem is.

On friday I did a 1hr "hard ride" and got an average of 290w.....which is low for me.

When I was disassembling the trainer I noticed that my wheel was not in perfectly and the tyre was rubbing against the frame. I then adjusted ther wheel position and noticed a much more steady and predictable power output that was nearer to 350 than 250.....

whoops ;-)

Damn some people have got things far too easy. Disassemble the trainer and bag yourself an instant 60watt 🙁

I have wet dreams about doing a 1 hr 290 Watt ride.

sounds like some people have watt-envy.

kant314 said:

sounds like some people have watt-envy.

me too fellas.....I would sell my soul to the devil for 450w FTP.

kant314 said:

sounds like some people have watt-envy.

yeah mate, big style 😄

BullGod said:

I'll start over from scratch again with the battery and config tonight.

don't worry about FT numbers.....no matter what your number is it still hurts the same for everyone!

Thanks for your help.

Damn I guess it was inevitable. The stupid computer has been a little eratic over the last two day. At one point while pushing 53/17 I was doing 96kph and my poweroutput was 256watts. Finally this morning it just shuts off completely. Damn I only had it for two months. So whats the deal peeps? Send it back or change the battery? 😠

I'd try and new battery first. only a couple of quid.
If that doesn't work, send it back