on August 21, 2011
Here is my review of the Kurt Kinetic Wireless Power Computer (`KKPC'). I have been using it almost daily for three months. While this review is slightly lengthy, I hope it will cover everything you need to know.
I originally chose this cycle computer for one obvious reason - its real-time calculation of estimated power output when used with the Kurt Kinetic Road Machine home trainer (`KKRM'). Widely regarded as the best home trainer on the market.
I like the KKPC because, of particular importance when being used out on the road, the screen clearly displays speed, heart-rate, journey time and distance all at the same time. The heart-rate monitor strap is of the budget variety with the thick plastic strap covering the width of the average chest, but as you probably already know it is unnoticeable even when worn as tightly as possible once you're out on the road and getting stuck into those hills.
I like the KKPC even more when cycling on the KKRM at home, obviously because it calculates estimated wattage which can be useful. It has been widely held, both officially and unofficially, that the KKPC's calculations are more than accurate enough for any sub-professional training purposes. The fact that KK bring this functionality for around £2k less than a new SRM crank setup is to be applauded.
It is therefore with regret that I must point out a number of major problems with the KKPC. These are issues which significantly detract from its otherwise excellent main features.
1. Of greatest significance when cycling on the home trainer is that the KKPC is unable to display both cadence and power output at the same time. Clearly the unit must be able to calculate both values at the same time, as the the wattage figure is entirely dependent upon the RPM feed by definition. Furthermore, it is obvious that anyone following a training DVD, such as the Spinervals workout DVD included with the KKRM, basic adherence to any home interval training is active monitoring of both cadence and power intensity simultaneously. Yet the KKPC does not allow this. Therefore, to do interval training properly with the KKPC you will need a second cycle computer with an independent cadence sensor in order to be able to see both readings at the same time. If the intended purpose of this computer was indeed to enable full participation in home interval training then the KKPC fails spectacularly by not allowing the display of RPM and wattage at the same time. Therefore, it must be said that the omission of this most glaringly obvious and basic function is a fundamental flaw which I believe is fatal. As if this was not enough to render the KKPC useless, several more significant issues follow.
2. The so called 'wireless' ability of the KKPC is bewilderingly limited to only the speed sensor and hear-rate monitor. For some reason which beggars belief, the cadence sensor itself is a wired unit. This means that on your chain stay bars running past the rear wheel, you will be required to install both the wirelss speed sensor approximately three inches from the rear hub, and the wired cadence sensor another three inches along from that. This is completely unnecessary. Especially when almost all other reputable brands of wireless cycle computer now employ a dual speed and cadence sensor, which is positioned so as to read the magnets on both your crank spoke at the same time. This is so basic that it is amazing that Kurt Kinetic (`KK') were not able to do the same. Furthermore, the fact that KK do not more accurately market the unit as `semi-wireless' is even more disappointing.
3. The installation of the wired cadence sensor is one of the most fiddly, inconvenient and fundamentally flawed tasks you will ever have to subject your bike to. The wire runs from the cadence sensor on the chain stay to the KKPC mounting bracket positioned on your handle bar. The wire must be affixed to your frame at various points throughout using household sticky tape. However, the unit comes with a wire a particularly long wire, and unless your frame size is something in the region of an XXXL, then you will have a ridiculous amount of excess wire when you finally route the cable to the front. The instruction manual unhelpfully advises 'wrapping any excess around your brake cables a few times'. Unfortunately this is nonsensical if you have even a remotely normal sized frame, for instance a 56cm. There is far more excess than your brake cables can ever support. I ended up wrapping the excess around the handlebars adjacent to the positioning of the mounting bracket. Then with some black plumbers tape I managed to make it look inconspicuous enough in the end. However, I still know its a badly designed bodge-job. A flawed design indeed. Especially when, in light of problem two above, a wired cadence sensor is totally unnecessary in the first place.
4. The KKPC mounting bracket for the main computer display is also limited so that it can only be mounted on a horizontal bar - ie your tops. It cannot be mounted vertically - ie on the stem. My previous Cateye had an incredibly simple mounting mechanism which allowed positioning either way. I resent not being able to mount my KKPC on my stem where I prefer it. This could have been easily avoided with a better mounting system.
5. Pressing buttons, to scroll through the various screens of ancillary data whilst on the move, is incredibly difficult due to both the terribly unergonomic design of the unit and the unresponsive nature of the buttons themselves. Anyone who tries using it, and who has previously used any other cycle computer, will probably instantly feel that scrolling for further data (such as HR/distance/speed averages, or switching from journey distance to cadence RPM) is just not worth the inconvenience and effort. Most other units on the market today require just pressing one, conveniently positioned, front mounted button. The KKPC button, on the right hand side of the unit, is simply too difficult to press effectively when riding. The fact that there are approximately ten screens to scroll through before getting back to the beginning makes this even worse.
6. Resetting your ride data mid-session, either when interval testing at home or when out on the road, is unnecessarily cumbersome and again quite beyond reason. Let me give you an example. You are doing your monthly 20 minute threshold average output test. You do your 10-15 minute warm up, and then wish to reset the unit in order to begin the test proper and enable the average wattage and average heart-rate data to be recorded just for the duration of that 20 minute period - ie not including the warm up period which you have just done. Doing this requires holding down both the left and right side buttons for three whole seconds. This is a surprisingly difficult feat. Far more difficult than any ride reset procedure for any other cycle computer I have ever used before. The two main operative buttons would be far easier to use if they had been positioned on the front face of the unit.
7. It must be said that the unit generally feels cheap and of poor quality. Despite a reasonable sized screen, the buttons have a cheap, clicky feel to them, and the housing of the unit itself feels low grade. A far cry from Cateye or Polar units at the same and lower prices. I appreciate that KK may be a smaller company with less R&D experience in this manufacturing field, but surely they could have outsourced the manufacturing of this unit to someone more competent. It is a unit which feels cheap and continually reminds you of it.
8. The spoke magnet which I received had not been manufactured properly. The small unit requires a screw driver to tighten a screw head inside a threaded housing in order to attach it to the spoke. However, the housing was too wide for the screw itself, and within 20 minutes of a ride the unit would loosen and immediately slide to the outside of the spoke adjacent to the rim, thereby depriving me of all further speed data, and thereby causing the unit to go into sleep mode after ten minutes of supposed innactivity, in turn depriving me further of even heart-rate or ride-time data for the rest of the ride. KK sent me a replacement. However, this was equally cheaply made. So I purchased an individual Cateye spoke magnet instead. This Cateye one was far easier to install and actually works.
9. As has been noted elsewhere, there is not data upload feature to allow analysis within the many free ride data software suits. That means that when doing personal interval testing you must keep a mental or physical note of your data. Only average and max power output and heart-rate readings are available. To be honest, this seriously limits that the power output function of the unit.
In sumamary, when in use at home the KKPC does not simultaneously display all of the essential training data that even the most basic interval training sesion will require, and is therefore extremely limited as a true home training tool. When out on the road, basic tasks such as resetting ride data and changing displayed data are so cumbersome that it makes you hardly want to bother. Using the KKPC is a chore. It is also never satisfying, because it always leaves you wanting more - more data, more ease in accessing to it, and a more ergonomic interface. What makes these problems worse, is that they are all completely avoidable. Competent planning at a product development level would have revealed and addressed these issues. No end of experienced cycling product testers would have said exactly the same as I am saying now as a humble amateur. From everything I have seen and read about the company, Kurt Kinetic seem like a genuine company that is trying to develop a true product. However, even with this KKPC, which I understand is the v2 (reported to be a significant improvement over the v1) there is still a long, long way to go. I hope KK read these comments one day and take them on board. They have the opportunity to improve the KKPC significantly further if they want to. I would recommend that they should do so as a matter or urgency.
Moreover, sitting behind all of this specific product evaluation, is the more general issue of whether having a wattage reading, only at home, is really of much overall benefit anyway. Is the concept of home trainer wattage estimated a good one in principle? That is too detailed a debate to have here. However, as anyone approaching amateur race-standard will probably know, real power development is obtained by having power data at the crucial ride points when out on the road too. Sure, the data is handy to have at home. And the KKPC saves you circa £2k for that purpose. However, heart-rate data alone is considered to be almost as helpful when used properly and in a non-professional training context. My view now, is that for someone who cycles predominantly outdoors, and uses the power readings only while during the occasional week night home session, the data is interesting but hardly essential. Three month's experience has left me less enthusiastic about this data then I was at first sight. The only real benefit which it offers is being able to track my true power performance increase over the weeks and months without having to do so on a less comfortable machine at a gym.
Therefore, £80 for the home power data seems to be of limited value. All things considered, it is probably only just about worth the money. But a cycle computer of this low quality really should cost only half that price. The power output readings are calculated from the resistance ratio as published at the KK website. The same conversion can be performed manually without a computer if one wishes. Therefore, on balance, this makes the KKPC itself decidedly poor value for what it actually is - a cheap cycle computer containing a glorified (albeit real-time) calculator.
In conclusion, the KKPC offers unique power output readings at home, which must be commended. However, as a cycle computer, it is badly designed and fundamentally flawed. It is a pain to use, and doesn't properly do what it is supposed to do anyway. From now on, I will only be using this cycle computer solely for my permanent home trainer setup and I will be adding another cadence unit to it separately. The KKPC is simply not capable of being a general purpose cycle computer in its own right, and this is a great shame, because it easily could have been. For these reasons, whilst I am occasionally pleased to have the power output reading at home, I generally do not enjoy using the unit during the remaining 90% of the time.
The KKPC is great in theory, but poorly executed in reality. For this reason, I can only barely recommend it - and that is only if you are fully convinced that you cannot improve your cycling performance with a heart-rate monitor alone.