New ibike user, old ibike model

[dpollard]

I have one of the older wireless ibike models (red button on top) that I have been using for a couple months now. I'm not sure how accurate it is (have nothing to compare it to) but it seems to work ok. There seems to be all kinds of calibration requirements with the newer models and I guess the reason for this is better accuracy. I'm not sure what more I can do with my old model to make it more accurate. There doesn't seem to be any calibration ride feature that I see so many references to in this forum. Anyway, as I said it seems to work ok and I would like to believe that the power output I've been getting is fairly accurate. The only time that the readings started to go out of control was after I put my racing wheels on. I should have probably done a new calibration but I didn't and I noticed that the wattage was a bit higher than usual. Despite the fact that I was riding faster with my racing wheels I didn't feel as though I was generating that much more power as the power output was indicating. However, the power readings started to shoot up even more after a few rides and I began ignoring it and focused more on my HR output rather than on the real-time power output. I would then download my rides to my computer and the iBike application would analyze the ride data and adjust the power readings to make them seemingly more accurate. I use the "just analyze without a profile" option.

Recently I did a 9-mile time trial. It was the 3rd stage of a 5 stage race for cat 4 & 5 riders over 30. Since I had not yet fixed the problem with the ambiguous power readings I focused primarily on keeping my HR above 170 bpm. I totally ignored the power reading as it was too high to be considered accurate. This was to be my first attempt at maintaining such a high HR for such a long distance. In the end my average HR was 169.4 bpm and my average speed was 26.2 mi/h. I had the fastest time and totally impressed myself and everyone else. The ibike software analyzed my average power to be 332 W. This is far and beyond what I thought I was capable of and I am wondering how accurate this figure might be.

Is there anything else I can do to improve the accuracy of the real-time power readings?

[Morocco Mole]

It depends on your total weight, but 332 Watts is probably close to the mark if this was a normal road bike and you averaged that sort of speed. My 20 minute FTP tests are about 355 Watts and I usually average about 25mph sitting on the hoods. On a TT bike you would probably only need around 300Watts to maintain that speed. Good effort !!

[dpollard]

It depends on your total weight, but 332 Watts is probably close to the mark if this was a normal road bike and you averaged that sort of speed. My 20 minute FTP tests are about 355 Watts and I usually average about 25mph sitting on the hoods. On a TT bike you would probably only need around 300Watts to maintain that speed. Good effort !!

Yes, it was a normal road bike with clip-on aerobars. My total weight (me+bike) was about 188 lbs but on the ibike I still had it set to my original weight of 192. I need to get a TT bike. Thanks. How often do you do your FTP tests?

[coachboyd]

Fit tests are supposed to be an all out test and they are really hard to prepare for. If you are doing a time trial that will take about 20 minutes, you can do it that way. . or you can just note your average watts for your 20K time trial (I'm assuming on the Boom road).

Keep in mind that if you change your body position to where you are more aerodynamic you will be faster while putting out the same wattage. The iBike will only see the increase in speed and will report higher watts. You will probably want to do coastdowns and a calibration ride on your time trial position so your watts are accurate.